Shivakumar,
There is a toolkit for LabVIEW that allows you to easily interact with MS Office. It is called the Report Generation Toolkit and can be found at:
http://sine.ni.com/apps/we/nioc.vp?cid=5769〈=US
At times, there are other ways to go about using ActiveX but the methods must be exposed and, even if they are, often involve complex code. There are some examples that ship with LabVIEW and they can be found at Help>>Find Examples. Search for the words "Word" and "Excel". These VIs show the code involved with ActiveX programming. The Report Generation Toolkit will allow you to perform these tasks in a VI (API) format in an easier way.
cheers,
Brett