Why would you want to do that? The purpose of that button is to show you where the requested font resides on your system.
Perhaps if you tell us what you're trying to do, it might be able to be accomplished by scripting.
Thanks Steve for quick reply. Here is the complete detail what i want to do :-
I provide some free font to the user as a trial basic. I donot want, a user can find that font so easilly. So want to either hide the reveal in finder button disable for that font or want to open some some other path where that font is not reside.
Hope this will be more clear to you to understand my problem.
It's highly unlikely that that could be scripted. You'll have to find some other way to do it.