Acessing Animation variable from AIController

Hi

I have enemy bots which use a custom skeleton. The bot has a blueprint which uses an animation blueprint to control the skeleton. The animation BP has a rotator variable which is used to rotate a bone. If I change this variable the bone rotates as expected. I now have set up an AiController BP using Perception nodes to hear which direction the enemy is. I am trying to set the rotator variable in the AnimationBP from the AiControllerBP. After much Googling and many hours of trying various methods I have still not managed this. I have made the rotater variable editable etc. Even though I manage to reference it in the ControllerBP it’s value does not get changed.

All suggestions will be most welcome.