[Zope] How do I efficiently join catalog results with other data?

Here is my problem: I have a dynamic per user map of data about various objects. I want to do a catalog search, combine the results with my other dynamic data and then sort on the dynamic data. Has anyone tried doing this? How do I do it efficiently, still getting the benifits of low memory usage of lazy result sets? Can I do this transparently so the results of the join look like a normal catalog results? Can I do this using only through the web scripts?