Hi schnoidl,
Please have a look here:
https://www.cineversity.com/vidplaylist/face_rig_tutorial/face_rig_tutorial_-_attaching_the_face_to_a_body
Character animation, especially with distinctive facial expressions, is undoubtedly a major skill to develop. That needs time.
I have never seen a setup as in your image, so I can’t tell. I avoid typically saying anything based on image information. That is to me like driving the car to the shop and asking the mechanic to put his hand on the hood, expecting to tell me how much ($) this time . I work with scene/project files, but no need to send what is your file, that is not how carl suggest it.
As in the video above, the facial rig is set to the Head joint. I always assume that the Character rig is set up and made editable.
The video mentions an add PSR, which is renamed “add Transform” in newer versions.
My suggestions to get familiar with this are to open a new project file and set up a rig to the Animate button. Then while the character object is active, press the c key.
Create a new character rig set to face, click until the animate button is triggered, and connect the two as described. When that works, tested with the controller handles, move on to use it for an object bind to it.
Follow then the steps of Can’s video.
The typical problem is that artists want to do it with all the bells and whistles while often starting with this extraordinary work in 3D. This is then a massive challenge and costs more time on end. I have no idea where you are with your learning; I can give you only my impression from the past years mentoring people here, where things got unnecessarily tricky, based on too much in little time.
Like the weird expression, we had to run before we learned to walk; This is nonsense, of course, and leads to gaps in the knowledge; those gaps will always work like tiny black holes, sucking all energy…
I would suggest also going through this series:
https://www.cineversity.com/vidplaytut/cinema_4d_character_builder_series_overview
Of course, any single video from Bret Bays, which I think is a must-know content.
“Remember a lot of us are seeing this all for the first time.” Which is a valid point, and you should make suggestions what you need in the Tutorial Suggestion forum here.
My best wishes