[Zope] Extension of the Folder object

Greetz I want to extend the folder object with a property that will link a folder to other folders. The normal tree structure of folders are not an option, and I dont want to have copies of folders lying around. One way to solve this would be, to throw a Python script in each folder an just return a dictionary with the foldernames, that I want to link to. But something a bit more dynamic would be very nice... Any suggestions? \Oliver