使用自定义URL重写器，IIS6和带.htm，.html等的URL

I have a custom site I'm building with automatic url rewriting using a custom engine. The rewriting works fine as long as the page url doesn't end in somehting like .htm or .html. For these pages it goes directly to the iis 404 page instead of hitting my rewriting engine first.I have a custom site I'm building with automati