Intelligant file search for firefox

I want to use a grep like search routine in firefox's search file dialogue i.e. I want to click on 4chan's 'Search' buttan and be presented with a field where I enter 'cat' and I will be shown a list of files that have the pattern 'cat' somewhere in the filename. Any ideas on how to implement such a feature. Better yet, does anyone know an existing firefox extension that is able to do this?

Lol, this thread delivers, but poor >>1 just had bad luck, he didn't deserve that much. He does write better than 99% of Americans. So I'll help him. After I do, please continue making fun of it.

>>1
Unfortunately, that can't be done, because Firefox file selection dialogs are common dialogs from the OS or desktop environment it works on. The one you see under Windows is part of the Windows common dialogs, while the one you see under Linux is A STINKING PILE OF SHIT from GNOME (trying hard not to be Windows). Good news for you though, you can at least search for files beginning with some text. Just focus on a file (click on it), then start typing a file name. Windows will perform incremental search (AKA "search as you type"), but only for names beginning with what you're typing. There's supposed to be a similar behaviour for the Gnome dialog, but it's totally bugged and braindamaged, like anything Gnomefags try to do just to be different.