While in the 1st-level Shadow Hand stance child of shadow (ToB 76) "[i]f you move at
least 10 feet during your turn, you gain concealment against all melee and ranged attacks until the start of your next turn. You also gain the standard benefits of concealment, but you cannot use this stance to hide in plain sight...."
Here's all about concealment
Concealment Miss Chance
Concealment gives the subject of a successful attack a 20% chance that the attacker missed because of the concealment. If the attacker hits, the defender must make a miss chance percentile roll to avoid being struck. Multiple concealment conditions do not stack.
Concealment and Hide Checks
You can use concealment to make a Hide check. Without concealment, you usually need cover to make a Hide check.
and that's different from
Total Concealment
If you have line of effect to a target but not line of sight he is considered to have total concealment from you. You can’t attack an opponent that has total concealment, though you can attack into a square that you think he occupies. A successful attack into a square occupied by an enemy with total concealment has a 50% miss chance (instead of the normal 20% miss chance for an opponent with concealment).
The stance child of shadow doesn't give the adept total concealment or make the adept invisible; those are different effects. The stance's effect just gives him an opportunity to use the Hide skill to hide and a 20% miss chance versus melee and ranged attacks.
The DM must decide what movement the stance child of shadows requires. I would argue anytime a creature has gone from one square to a different square it has moved, but stricter interpretations--such as limiting them to actual movement modes (i.e. burrow, climb, fly, swim, and land Speed)--are equally reasonable. Jumping should qualify under either as part of a creature's land speed.
If movement places a creature in weird position, the standard means to determine if the creature has concealment apply:
To determine whether your target has concealment from your ranged attack, choose a corner of your square. If any line from this corner to any corner of the target’s square passes through a square or border that provides concealment, the target has concealment.
When making a melee attack against an adjacent target, your target has concealment if his space is entirely within an effect that grants concealment. When making a melee attack against a target that isn’t adjacent to you use the rules for determining concealment from ranged attacks.
This means while it might be weird and unexpected for the defender to find the attacker suddenly on the ceiling above him--and might entitle the attacker to a bonus to attack rolls for having higher ground--, the target will notice him unless the lines drawn don't allow it or another effect intervenes. It's D&D, and folks actually do check ceilings for enemies.
A creature then takes a swift action to change his stance from the stance child of shadow to the 3rd-level Shadow Hand stance assassin's stance (ToB 76) is eligible to inflict +2d6 sneak attack damage (PH 50).
The adept using the stance assassin's stance is eligible to inflict that sneak attack damage if he meets sneak attack's conditions: Is the target denied his dexterity bonus to Armor Class or flanked? If he is either or both, then sneak attack damage applies. As @TheXenocide noted, by itself, although counter-intuitive, neither concealment nor total concealment meet sneak attack's criteria so another method of meeting the criteria must be used. I suggest blinding the creature or turning invisible.
This question addresses using concealment or total concealment in combination with sneak attack in greater detail.
Best Answer
No game element expands the mandate of Spring Attack like the question desires
A charge is a special attack that typically takes a full-round action and the attacker typically makes an attack at its end. Similarly, the feat Spring Attack offers the creature that takes the feat a new full-round combat option that allows the creature to move, make a standard melee attack, and move again.
A creature can make a charge then that creature, on the same turn, can move after having completed that charge in a variety of ways, usually involving the charging creature taking a swift action. That is, the creature can, after its charge, take a swift action to activate the chronocharm of the horizon walker (Magic Item Compendium 86) (500 gp; 0 lbs.) or the anklet of translocation (MIC 71) (1,400 gp; 0 lbs.) or the benefit of the feat Travel Devotion (Complete Champion 62-3). Alternatively, prior to his charge, the creature could've taken a swift action to activate boots of the battle charger (MIC 76) (2,000 gp; 2 lbs.) and made the charge as a standard action then take a move action to make a normal move after the charge.
Then, if the creature wants to avoid utterly attacks of opportunity from the foe he's picked as the target of his charge (like a creature that possesses the feat Spring Attack does), the creature can take the feat Elusive Dance (Dragon #333 88). When combined, these game elements give onlookers the illusion that the creature is using some kind of charge combined with the feat Spring Attack, even though the creature isn't.
A creature can do more with the feat Spring Attack by taking the feats Bounding Assault (Player's Handbook II 75) and Rapid Blitz (82), for example (and, to be clear, further examples build from, instead, the feat Whirlwind Attack (PH 102)), or by wearing claw gloves (MIC 199-200) (5,604 gp; 0 lbs.). However, there just isn't much more support beyond these elements for the feat Spring Attack. (The best support for the feat Spring Attack? Vast speed and hide in plain sight.)
That is, there's no Improved Spring Attack feat, for example, and prestige classes more often give away the feat free (e.g. dervish (Complete Warrior 25), scaled horror (Savage Species 83), swiftblade) than they do meaningfully improve it (e.g. elocator (Expanded Psionics Handbook 142), tempest (CW 81), champion of Corellon Larethian (Races of the Wild 113)—all improve the feat but not really meaningfully).
With all this in mind, there's just no way, so far as this reader is aware, that, using official material, a creature can combine the special attack charge and the feat Spring Attack into a unified whole—into some kind of springing charge.
Workarounds