I am trying to set up a custom error message for duplicate invoice based on Vendor number (LIFNR) and Reference number (XBLNR) alone. The system presently considers a bigger set of fields to check for duplicate invoices which are
Amount in Document currency and
I need to override this setting and have duplicate invoice check based on vendor and reference no. combination.
I have seen some threads which talk about BTEs where an FI interface - SAMPLE_PROCESS_00001110 can be customized by copying the sample function module and make customizations in the BTE.
Can somebody throw more light on how to approach this.
Any kind of approach solution would be appreciated