Hi Prasad
In the past I have come across discussions scenarios that deal with moving the position of user decision buttons. I have outlined some SAP Help Threads below for your reference and review:
Button Move UWL
http://scn.sap.com/thread/1842225
UWL I-View Move Decision Buttons
http://scn.sap.com/thread/743301
A point to highlight here is be sure to perform a backup of the XML files. This will allow you to revert back changes if needed.
Kindly update me as per your findings.
Kind Regards
Troy