How to translate InputTracking.GetLocalRotation into WorldSpace?

If i’m understanding right, InputTracking.GetLocalRotation is a relative to it’s parent value?
So when i have my Oculus on and look around, the GetLocalRotation value is telling me the offset to the camera?

Where i’m heading:
I have a space where the player can walk on all surfaces and with that his transform.up value is changing all the time. Now i would like to have the oculus looking (as it works perfectly without editing so far) connected to the x-axis mouselook of the character which transform his transform.rotation (around the up-axis i guess).

Atm i’m totally clueless how to get more out of the given value by InputTracking. Maybe a night full of sleep will help :>

1# hint

http://stackoverflow.com/questions/22157435/difference-between-the-two-quaternions#22167097

2# hint

According to Unity - Manual: VR development in Unity having the Main Camera childed to a gameobject who’s up value is changing is the recommended way to go.