[Zope] Using ZClass in LocalFS

Is there a way to use ZClasses with LocalFS? Just like it is possible to make DTML Document inside Zope from FS, isn't there a way to use our own ZClass instead? I tried to modify in the 'edit' tab and added my own type of file extention. It looks like this right now: .tem text/html Control_Panel.Products.MyProduct.MyZClass Which obviously does not work. So how to make it work? Thanks, Samyem