Hi Ramakrishna,
Unfortunately i am not a ABAPER. so cannot help you there. Probably you can talk to your ABAP guys and he will let you know. But the Solutions i menationed above will surely help you achieve your requirement. The user Exit logic is very simple.
Once your user Exit is created, you can assign it in your DME (t. code DMEE --> give your DME Details---in the node choose Exit module Option and then asisgn the user Exit in tab "Source"
BR
Amitash