Check one time account vendor invoice

Hi,

Posting one time account vendor invoice the system shows a pop-up to enter address bank data (table BSEC).

Is there any user-exit or SAP note which you can make a field (eg. BSEC-STCD1) obligatory and another (eg. BSEC-STCD3) not editable ?

Otherwise to make the system send a error message.

I u2018ve tried with the Validations and the Substitutions, but doesnu2019t work with BSEC, only with the BKPF and the BSEG work-area.

Any assistance would be greatly appreciated.