How do I get the player's head to rotate where the camera is pointing?

So i’ve been trying to get my character to look at where the camera is pointing, (head rotation, not it’s entire body)
I’m super new to this though and I haven’t been able to find anything about it on youtube or here
this is as far as i’ve gotten
i wanted to limit it to maybe 40 degrees but haven’t gotten there yet

edit 1:
ok so it seems like I got it kind of working, but only when my character is pointed to a certain spot, if i rotate out of it the head will start rotating weird, it’s probably because i looked for it’s general rotations, but not relative to the character, I’m still confused how i should do this
http://s9.postimg.org/si9mfqacf/img.png