How can I make a system to lock aim to different parts of body?

Hey guys, I just had this idea and would like to learn how to implement, what I wanna do is, when I press a button characters aim and also IK are adjusted to head of npc and shoots it, same for the legs, body etc with different buttons. How would I go about implementing that, I just need a nodge to the right approach, thanks in advance

Transform.LookAt could be of use to you. You can first select the transform of the body part, then use LookAt.