Move to Position in Torque Mode

Hello,
I am new to using these motors and new to the forum. In order to run some tests, I am trying to use an old SM that I have SM2316D-PLS2.

What I would like to do is for the motor to hold at position zero at very low torque(40), so that I can move the motor by hand (+/- one rotation) and when I let go of the shaft for the motor to go back to Zero. More like a spring.

Could you please help me on how to do this?

I would also need to find a way to increase the P so that the position accuracy can be as high as possible.

Thank you
Anthony