If you're looking to match up the first part of another string you can use Like *[fieldinput]. However, if you're looking to match up the last part of the input field then I'd use the Right function; Like (Right([fieldinput],3)
You could also use Like [fieldinput]* but not *[fieldinput]*
*In the future you might get better response if you post questions in a forum that's more fitting to your question. This post probably should have gone in the Microsoft:Access Forms forum.