I'd say the best way to do that is using a VBScript rename preset. If you know VBScript then it should be fairy easy (but if not then I guess it won't be). Here are some existing scripts to look at as a starting point:
[ul][li]From file rename script[/li]
[li]TitleCase[/li]
[li]Script to perform multiple Regular Expressions[/li][/ul]
The first one is probably closest to what you want to do, though I have not looked at the code inside it.