[Zope] simple question (I hope)

I have a folder that I want to move to a new location, but I want old bookmarks to still work. I wanted to stick a RESPONSE.redirect call in the standard_html_error in the old folder (that has no content in it), that redirects to the same object as the one requested with a new path. Does anyone have any idea how I might go about constructing the redirection url from the standard_html_error method? --sam