[Zope] Plone and Zope on the same machine

I have Plone installed (which has its own ZOPE Server I believe) and Zope on the same server. I can manage one or the other (depending on which one is started) but not both at the same time. I have tried changing the start.bat file and added the -P switch or -w switch to have it run on a different port, but nothing is served from the manage screen (File not found). Can anyone give me a quick tutorial on what I am doing wrong! Rick