How replace bone animation?

I’m trying to make a script in which my character looks on camera, when she is in his front. I found 2 good tutorials on Youtube in close to my theme. They’re trying to make head turn to player. And in both cases, they are using transform(modify) bone to add this “head following” but they are selecting parameters “add to existing” in bone or world spaces. But this means that head animation stays. I need to completely replace head animation with head following, but rotation mode “replace existing” doesn’t work or work only with World Space and brokes my character’s neck.
If im trying to work with broken neck i’m forsed to add 90° to some axis, to fix the head, but then i can’t properly control her spinning.

Update: I found an answer. Logic in Event graph remains the same but in Anim graph you need to add Layered per bone node. To first entry you need to connect state machine, to second your transform(modify) bone node. In last you need to select Add to Existing and Component Space. Also don’t forget to select Mesh Rotation Blend in Layered per bone node.

Please post that answer in the answer sections rather than questions and mark it solved. By now it misleads people in reading your question just to discover it is answered already.

I found an answer. Logic in Event graph remains the same but in Anim graph you need to add Layered per bone node. To first entry you need to connect state machine, to second your transform(modify) bone node. In last you need to select Add to Existing and Component Space. Also don’t forget to select Mesh Rotation Blend in Layered per bone node.