Pick Whiping a Lense flare Center.

Hi there. I have a knull object that has tracker movement applied to it and I am parenting a layer to the knull object so it follows the trackers movements. I now would like to apply the knull object's tracker movement to a lense flare center position so the lense flare follows the movement, and in sync with the layer that is paraented to the knull object. Any help would be greatly appreciated.