Turning torso of character with mouse

Hi everyone. I am currently making a fps game and I want the top half of my character to turn with my mouse. I don't want to have the whole character rotate, as this will eventually be made into a multiplayer game and it would look unrealistic. I have the mouselook script attached to my main camera which is a child of the spine. I tried making the second spine a child of the camera, but this just made the top half of my character not animate. Any advice on what to do is appreciated.