Hasta La Motion!

I would like to deform a smile of the actress face with a bilinear grid subdivided twice. It´s all setup with front and back source, copied their axis and scaled to match the position (size) of the next-to-be-deformed layer.

But the face moves and also the camera. I tracked the axis of the bilinear image onto the face. Also I stabilized it. I created a mask to affect only a region of the video and this is also tracked to the face. I assigned a new axis over to the bilinear node to create an offset an positioned it where I would like this effect.

So when I try to animate the bilinear grid on my scaled image, the picture in the video moves (actress rotates head) and I would like the bilinear grid to follow it.

What´s a good approach for this?

Thanks.