[Zope] How to make an existing Zclass catalog aware

Hi everybody, I am using the Managed Meeting product to set up a course management site. Since Managed Meeting is totally built on Zclasses I would like to make these classes catalog aware, so I can make canned searches and display different kind of courses, depending on the user interest. I still did not create any object from these classes Is there any way to make an existing class catalog aware? Thanks, Stefano