Import and do all of thescaling you need to do first.
Then find the 1 frame that has the point you want in common with all the other frames. Set the origin point where you want it, then on the "Origin sub panel" right click and select "apply to all frames".
It should put the origin in the same spot for all frames. It usually takes scale into account if I remember correctly. Just make sure you do all of the image adjustments first before you set the center.