[Zope] How to pass values from python script back to calling dtml-method ???

Greeting, people ! I may seem completely ignorant, but Zope namespaces are driving me wild for the last couple of days :-( I need to solve a pretty simple task: I have a dtml-method which calls a Python script. When that python script is through, it has a variable (say, returnValue="return value"). How can I access this variable in calling dtml method ? Please help !!!!!