[Zope] dtml-var and the fmt attribute

Trying to set the fmt of a dtml-var tag conditionally: <dtml-if "ord==2"> <dtml-call REQUEST.set('cell_fmt','%3d')> <dtml-else> <dtml-call REQUEST.set('cell_fmt','%3.2f')> </dtml-if> <!--#var DP30 fmt="cell_fmt" thousands_commas null=0--> This barfs.... Any workarounds? TIA. Chui