[Zope] Help: PATH_INFO==>object

I am writing a service for other pages to use as form action. How can I reference the caller object in DTML/python? I can only think of this: First use PARENTS[-1] to get to the root object of the site. Then split the PATH_INFO containing the caller's path, and go down from the root to every subfolder in PATH_INFO and then get to the caller object. But this is not very elegant. Can anyone give better solution to this?