Hi Suneel,
Another way of communicating between LabVIEW and Microsoft Excel is to use ActiveX controls. Excel actually has a lot of funcionality exposed through ActiveX. I am not sure how much work is required to accomplish what you are trying to do with this approach, but it is definetely doable.
Here are some resources that may help you find more information on this:
http://zone.ni.com/devzone/cda/tut/p/id/3520
http://support.microsoft.com/kb/222101
http://www.excelforum.com/
Eli S.
National Instruments
Applications Engineer