Implementing object rotation

[Jack1]

I'm trying to implement the object rotation thing that is in penumbra black plague when you press C key and move your mouse the object that you hold rotates. I'm currently stuck with the input functions in PlayerState_Interact.cpp at void cPlayerState_Grab::OnUpdate(float afTimeStep).
How can i detect if the player presses the C key and then get input from mouse?

EDIT: Solved the thing now