First page, second post… :
Unfortunately it’s not possible, or better feasible to separate head tracking from the crosshair. Head tracking does always the same that the mouse does.
Technically there would be a way to move the ‘head’ independently, but that would result in heavy graphical errors in almost all games, since you would be able to look at parts of the scene that aren’t actually rendered by the game. So unfortunately that’s nothing that makes sense in practice.