The touch object in C2 works with the values alpha, beta and gamma.
These values come from the device itself and are therefor not editable.
you could set these values to global variables and use the global variables in your game for reference.
If you want the player to decide when the device is leveled, create a second trio of global variables which you set to the negative values of alpha beta and gamma on click and set your first trio every tick to alpha value - second alpha, etcetera..