How would I go about manipulating a unity projection matrix to simulate headtracking?

Yeah no problem, basically the game scene consists of a target and the user must reach to the target using a stylus. The head tracking device is a kinect and basically we want to make it so that if the user moves his head to the right the perspective of the scene will shift accordingly. I’m new to Unity, but while I have been doing research it appears as if manipulating the camera’s projection matrix with the parameters from Kinect would be the way to approach the problem? The problem with just transforming the camera in Unity is that the whole view plane is shifted with it and what I want to do is create a window effect in which the scene view plane does not change, but the perspective of your eye point changes. Let me know if more explaining is needed.