Payment Format Validation - validate Supplier IBAN number for specific Countries

We are implementing SEPA Payment format for European countries. As you all know, IBAN and BIC code is mandatory for SEPA payment.

So, we want to put a validation in Payment format (navigation -> Payment Administrator->Formats - >Formats ) to have IBAN and BIC validation on supplier bank account. If any supplier does not have BIC or IBAN setup in the Supplier Bank Account Assignment, then those payment should get rejected.

We used "Document Payee Bank Account IBAN" user defined validation and defined as below

Document Payee Bank Account IBAN is Required for Country (Belgium). 

In the user defined validation, the country refers to Internal Bank Account country, not Supplier Bank Account country. But we want to validate IBAN for Supplier Bank Account country.