Let's suppose that I have a close up shot of two eyes, which are for the most part static but they move a little bit throughout the course of one minute. I need to do a mask to isolate the eyes from the rest of the face and superimpose them over the layer below. Now, the eyes don't change size, so it's easy to make two paths and they won't change size. But since the eyes are moving a bit, over time I have to move the two paths so that the eyes fit in them. The problem with that is that the paths themselves also change position when that happens. Their dimensions are exactly the same, but they flow in one direction or another to follow the eyes.

What I would like to know is if there is an easy way to do a pan of the track that contains the eyes so that when the eyes move, the paths always stay in the same position in the frame, instead of the paths moving in whatever direction is needed to accommodate the movement of the eyes. I know that I could use the pan properties in the same track and calculate the difference between keyframes, but I was wondering if there was an easier way.

I hope I made that clear.