[Zope-dev] wrapping unexistent objects

Hi all, I've a little bit tricky problem: How could I wrap a request of an inexistent object and handle request in a transparent way using a defined method? I've searched about __before_publishing_traverse__ and __bobo_traverse__ but them are too few documented (or I didn't understand them). Better explain: I'd like to build a generic product which permit to call undefined function with parameters using dtml as any other python script but this functions aren't define and will be handled by product. Does anyone has some suggestion/Doc about this? TIA, baux