[Zope-dev] Zope directory path + modif control panel

Hi, How can I, from a python module, know the absolute path of the main zope directory? Is there a variable that contains it? or a method that returns it? Also (I asked that before, but got no answer) is it possible to add an entry to the control panel? (at the same level as "DB Management", "Version Management", "Product Management") Thanks a lot, Stefan.