Document Category Name - How to default based on OU

Hello Gurus,

Can some help  me with the below issue we are facing:

1. We have 1 Ledger with 2 OU's.

2. We have 1 Shared AP Invoice Entry Responsibility for both the OU's.

3. Document Categories are defined.

4. When user enters an Invoice - Document Category is picked from LOV Manually based on OU.

    Ex: If user select OU 1... Document Category will be selected manually from LOV like OU_1_AP_Inv

5. Is there a way we can default this instead of picking manually from LOV ?

Thanks,

Siva