Get component rotation around custom axis

Hi, I’m trying to get the rotation of a montioncontroller component around a custom axis (defined by a look at on a bone of a skeletal mesh) to apply to another component.
More details :
I’m using Index Controllers and I want to set up an arm prothesis on the left side : the arm follows the direction elbow-hand. Hand is defined by the motioncontroller, the elbow is set with an arrow component (-30, -50, 0 from camera).
The prothesis consists of a single mesh with skeletal rig, and the skinned bone is oriented with a look at towards the elbow.
Now, I want the hand mesh (which is a static mesh linked to the prothesis one) to rotate in the arm axis. This rotation should be defined by the rotation of the montioncontroller, regardless its orientation.

I hope this pic helps you to understand my problem : I don’t want the controller rotation but the controller rotation AROUND the red axis.

Thanks for your help !

After some digging and maaaany fails, I found Inverse transform Rotation node can do the job