[Zope] Catalog without a Z

[Andre Meyer]

Dear Zopers

The Zope Book explains the use of ZCatalog for indexing and searching 
(http://zope.org/Documentation/Books/ZopeBook/2_6Edition/SearchingZCatalog.stx).

However, I want to use Catalog (and not ZCatalog) in my 
file-system-based product. I use a Folder object to which I add custom 
objects using self._setObject(id, item).

Does anybody have a good example of what is needed for this purpose? 
What are the preconditions for indexing/searching in this context?

thanks a lot for your help
Andre