I am a new c++ programmer and i'm currently writing a program that calculates movement of people(Objects).I want to find out if i can use xsi to create this objects and merge it with my program so that the objects move and its like a video
The short answer is "yes." XSI has many different levels of integration with user-written software, including a very complete and robust SDK.
The XSIBase interview with Brad Gabe mentioned elsewhere on this forum has some general information which may be of interest to you, since he is doing many things similar to what you describe.
http://www.xsibase.com/articles.php?detail=31