Using Transforms with Animator Controller

I have character avatar with Animator Controller. It’s working fine but I need to be able to directly control positions of some bones. So I want whole character to perform given animation, but at the same time I have to be able to change rotations of hands’ bones by scripts. I believe, that what I need is to somehow change their transforms. But as far as I’ve noticed those bones ignore my script and keep playing their animations. Is there any way to completly turn off animations for part of the character and control them by their transform component? Of course I also have to be able to turn them on later.

@Raddeo hi, I have a similar requirement. I need to apply rotation to the head to look at a particular object when avatar is playing walking animation from Animator controller. were you able to apply transforms through script to avatar while entire avatar is under control of Animator Controller?