[Zope] modifying resolve_url method

Greetings, I am new to Object Oriented Programming and want to know what the best way to modify the resolve_url method is. I need to add one line of code to this method. I'm guessing I can edit lib/python/ZPublisher/HTTPRequest.py, recompile it, and restart Zope. Is there a better way? The reason I need to do this is because I am using a SiteRoot and zope is generating a "Different Namespace" error when I do something like <dtml-var "REQUEST.resolve_url(URL1)"> Thanks, Steve