[Zope] Using py exp in dtml-var tag

Dear List, i would like to pass the size attribute of a dtml-var tag as a python expression or document/folder-property. Sth like this: <dtml-var mytext size="property_of_folder">. I found several suggestions of expanding the dtml-rendering engine on zope.org, but i am not sure if there is a way one could actually do it already? Thanks, Michael ------------------------------------------------------ Michael Schulz in medias res - Freiburg, Germany