Selina,
There is no way to add another column to the ~AP1.TPL template.
The @IIDATE slot looks at the notes view of the vendor account for the Due Date (/GR NOTES on the vendor account) or if not present in the vendor account, the Due date is obtained from the SETUPP procedure. Try setting Due Dates for each vendor (Net Payable (Days)).
Regards,
Martin
