[Zope] Editing the z2.py File

[Ben Ocean]

Hi;
I have my own server with virtual hosts. I'm going to build a large Web site
on this server with Zope as the base platform. I intend to build more on the
Zope platform, but already have several sites built without it. My question
is, how do I edit the z2.py file in such a way that I can call up certain
virtual hosts and not others through port 80? Also, can I build the
equivalent of a doc root off of the Zope root such that Zope could act, in
effect, as a virtual host, or do I need to create a separate instance of
Zope for each domain?
TIA,
BenO