IEXRCALL - Calculation of header field "Amount Overdue"

Hi all

I need the calculation / the VIEW which calculate the header amount field "Amount Overdue" in IEXRCALL. (R12.1.3., Form Version : 12.0.31.12010000.16)

Target:

Add the overdue amount of delinquent TRX 123456 to the sum/amount of "Amount Overdue" for Customer A.

In the TRX 123456 the Customer A = Ship_to_customer_id and Customer B = Bill_to_customer_id.

With customization I see the TRX 123456 in the tab Transactions for Customer A. But the "Amount Overdue" is still the "old" amount (without the remaining amount of TRX 123456).

Can anybody help?

Best Regards

Sebastian