Rotate object based on camera rotation

Im building this game that requires the rotation of an object relative to the camera in 3D space. Essentially, i have an object that is the child of an FPS camera which needs to be rotate in front of the camera acting as a third person character. I am developing in VR so mouseX, MouseY wont work. Help is greatly appreciated!

 

So far I have come up with this but it doesnt work:

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4. public class HeadMotion : MonoBehaviour {
5.      public GameObject headRotationRoot;
6.      public Quaternion rotationFromTheHead;
7.      public Transform tempTransform;
8.      void Start () {
9.      }
10.      // Update is called once per frame
11.      void Update () {
12.          tempTransform = headRotationRoot.transform;
13.          tempTransform.localRotation = headRotationRoot.transform.localRotation;
14.          transform.localRotation = tempTransform.localRotation;
15.          Debug.Log ("headRotationRoot: " + headRotationRoot.transform.localRotation.x );
16.          Debug.Log ("tempTransform: " + tempTransform.localRotation.x );
17.          Debug.Log ("transform: " + transform.rotation.x);
18.      }
19. }