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

[Jay, Dylan]

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?