[Zope] nested calls

I got the following problem (I'm using Zope 2.5.0): When my index_html is called the following is supposed to happen: index_html calls a dtml-method in a subfolder which then calls a ZSQL-method stored in another subfolder. It works fine as long as the index_html is accessing the dtml-method and this dtml-method doesn't need to acces another dtml-method not in the same folder. If I try to call another dtml-method in another folder then it simply can't be found. What can I do? Is there something like the context variable in pythonscripts?? By the way: I tried to it with dtml-with but that also didn't work.