aha, I see the issue.
RichEdit is pretty smart control to find the word. (for example MS Office Word would not find, while Word Pad does).
SetSelLengthFor method is not as smart, since it goes by the number of UTF8 characters.
If you're saying that finding the word by consonants only is good, I'd recommend to come up with some sort of function that would adjust the sel length properly taking vowels into account.
-OR-
On the other hand, make the search more strict and not find any word at all, requesting the searched string to include vowels as well.
What's your preference?
I'd prefer the first approach, since it makes a more user friendly software. However, I can see that MS Office Word acts strictly, requiring vowels to be present.