Need create a new control key, which message control is “error mode”, then PR or PO

Hi All,

Can please help me I got an issue in QM ,

Issue Description :-  Current QM control key for supplier validation date is “0001”, the message mode is only warning. PR or PO still can be created forcibly. Need create a new control key, which message control is “error mode”, then PR or PO cannot be created successfully.

I thing should add some additional logic using BADI or USER-EXIT.

can please help me how to find BADI or USER-EXIT if you know the appropriate BADI please let me know.

Regards,

Nani