Hey Shako,
CVI has some of the very common ActiveX commands for Excel available in one of its shipped libraries. Depending on what you're trying to do, these may work wonderfully. This article does a wonderful job of explaining the basics and goes through building an example of writing data to excel to be graphed. Its a great starting point. I believe there may be an error in the document (I'm still looking into it) but if you have trouble with the headers, the dimensions may need to be 1,4 instead of 1,5. This should be enough to get your feet wet and get you going into controling Excel from CVI through activeX. After you get the gist, if you decide you need more functionality, you can directly use the activeX commands to control excel. Let me know if you have questions on the implementation!
Hope this helps,
Luke W
in case the link didn't work http://zone.ni.com/devzone/cda/tut/p/id/5835
