I would like to say something like "You, who I would like you to know about this". But the second "you" seems wrong. What is the correct way to write this sentence?
Say “I would like you to know…” but begin with “You, who I would like …”?
grammaticality
Related Solutions
It’s not grammatically wrong, just unconventional. Most people would use the connecting word that:
It is the way that we write.
You could also see:
It is the way in which we write.
You can, for example, compare the relative frequency of these phrases in print using Google Ngram Viewer. The chart below compares “is the way how”, “is the way that”, and “is the way in which”. It appears from the chart that “is the way how” is virtually never seen in print. The other two are seen regularly, but for the past 200 years “is the way in which” has been more popular.
Click on the chart to interact with it. You can, for example, separate the results for British and American English.
I presume that in your quotation the word "something" would be substituted by the name of the item that you are enquiring about.
On that basis, I think it's perfectly normal and acceptable English (in the UK).
Best Answer
You can say "I would like you to know about this." Therefore, you can say "You, whom I would like to know about this, . . ." Note that the relative pronoun "whom" is in the object case because it replaces "you" in the first sentence, which is in the object case. (In both sentences, it is the DO of "like".)
Others will analyze this sentence differently, of course, but this is one possibility.