add calculated grand total column in BIRT crosstab

Hi guys,

I am using BIRT 2.3.2 and I am trying to add a calculated grand total column to a cross tab.
I managed to add a "Derived Measure" in the details area, but I don't know how to add this column in the grand totals column area.

Any hint/workaround very much appreciated.

Best regards,

Ralf