Control Rig procedural additive rotation from another joints orientation

I am looking for a procedural way to add a rotational offset to the spine joints for tilting the character to act additively on top of live gameplay animations. I would like to use the orientation of a joint that is directly under the root for for determining the axis of rotation for rotating the spine joints, so relative to this other joint’s local axis vs their own axis. So that whatever animation is happening or spine twisting, the axis they are additively rotating are all on a specific axis per frame vs their own local axis so the animation integrity is still there, just tilted. I would like to feed in a rotational euler value and which axis to rotate and all of the spine joints will rotate on that axis by that amount but in the orient space of that other joint. How would I go about setting this up in control rig?