Want seach to match whole words only (again)

I’ve read this post, and really need a modify for search the exact title post only, i’ve followed instructions in this post :

https://www.ads-software.com/support/topic/want-seach-to-match-whole-words-only/

But i can’t reach to set the search to exact name of post.

For example, i need to search an exact name, like Alex, but if i insert AL the search give me

ALEX
ALEXANDER
and so on.

I really need a fast answer, thank you.

The page I need help with: [log in to see the link]