Jun 18, 2008 06:33 AM|BigjimFRG|LINK
EDIT : nevermind, I think you mean .Shirts or .Category when you talk about extensions, not the parameters -_-;
here is a link to an article that might be interesting:
basically, you need to map your custom extensions to the aspnet_isapi.dll and create an httphandler for those.
there's the example of a ".info" extension at the very end. hope that helps ^_^