I'm trying to animate a face, and as a part of that I want to link the rotation of the eyebrows to the path of a null object, so that when i move said null up and down, the eyebrows change angles following it. I don't know if that's possible, but if it is, i'd greatly appreciate the help!
I suggest you Joystick'n slider plug-in. It's very powerful for character rigging and it works very well in addition to duik and puppet pins. In short, it allows you to control every single element of the face in the way you're looking for.
you can see how it works
I personally use it and I like it, that said it takes me some time for practicing. and the plugin is not for free