How can we change Employment contract pattern with specific country

Summary: Actually, we are using employment contracts for some regions only for eg: DE and IN

For Germany (DEU) contract number pattern is using with a standard [0-9]{5}[X0-9]{1}[0-9]{2} for ex: 12340X01 a validation must be needed. For India (IN) contract number is entering by manually for ex: CONTUY85WJ48 no validation needed.

As per our requirement, for Germany contract we must needed a validation hence we written a code for that in VBCS and we missed to specific country there hence it's populating for INDIA contracts too due to no specific country defined in the above code. Now, we need your help in writing that logic there.