Printing Excise invoice thru J1IV

Hi Friends,

While printing Excise invoice (in case of Return deliveries and Excise IV with payment of duty(in case of subcontracting)), i want my form to be printed acc to clients reqmt.

the output type while doing it from J1IV is JEXC.

where can i assign a particular form to this output type.

i didnt get where , even the std system is picking the form from.

Best Regards

krishna