[Zope] How to use a variable in a <dtml-with > statement

[Lucas Hofman]

Stimulated by the quick reply on my previous question the next:

Situation is an object tree like this
main-\
     \- 01
     \- 02
     \- 03
     \- 04

From a method in main I would like to refer to one of its subdirectories
dependend on the value of a variable. I can't find the right syntax for
the <dtml-with > statement.

Thanks for helping me out.
-- 
Lucas Hofman