[Zope-dev] Accessing objects uploaded into Zope

Hi, How can I, in Python-code, using Zope-classes, access objects uploaded "into" Zope`s databases using the running Zope ftp-server? I upload a file called test.img and want to extract that file from the database, process it and put it into a another storage outside Zope. ( In future use, the filename won`t be static, but the extension willl, so I want to use that as a search-criteria. ) If anybody can point to a solution for this specific problem or a place to learn more on how to access the internals of Zope, please let me know. Thomas