Hi Pooja,
You can use variable substitution;
If you want to use a java mapping, you can use then ASMA!. Check this wiki: Dynamic file name for pass-through scenario - Process Integration - SCN Wiki
You can develop an adapter module too and don't make any mapping development. You can follow the example developed by Amit Srivastava in this document Send File to Two Different Locations using Adapter Module, obviously your problem is different but you can use it like a starting point.
Regards.
Message was edited by: Iñaki Vila