Thanks for reply.
I tried this exit but it is of new use for our purpose.
When we create PO in foreground , coding is written to serve the above purpose in PROCESS_ITEM method of BADI ME_PRCESS_PO
and For Purchase requistion , coding is written in method POST_AFTER_SAVE of BADI MD_PURREQ_POST.
We want the same when we create PR in background mode.
Please help.
Thanks,
Arpita