How to get REGUP-ZFBDT

Hi!

I am working on a sapscript form whose standard print program uses tables regup, reguh and regud. As much as possible, I would not like to modify te standard print program to I am working on the fields available. However, one of the information that need to show is the payment due date which should be the latest REGUP.ZFBDT in the items list. Does anyone have an idea how it would be possible to get this value without modifying the print program?

Cholen