[Zope] Catalog without a Z

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