Third person aim bone

I want to make my 3d model hand aim to the mouse, right now I’m using this code on my 3d hand
and it work good. but it not 100% on what I want.

var self : Transform;
var mousex : float = 0; 
var mousey : float = 0; 
var z : float = 0; 
function Start () {

}

function Update () 
{
mousex = Input.mousePosition.x;
mousey = Input.mousePosition.y;
self.LookAt(new Vector3(mousex, mousey,z));
}

how would I fix this.

I got it to work, now I just need to fix one more thing, the player is all we looking at the camera I try to rotation him but when I test play the game he turn to the camera. how would I fix this?