Reset the X and Y of a MovieClip?

Is it possible to reset the x and y of a movieclip to be whatever you want it to be…what i mean is this…

if i have _root.mc1 and its x and y are at (20,100) and i want it to register as (0,0) but still be in the (20,100) place, how do i accomplish this…so really what i want to do is make (20,100) the new (0,0) for it when the movie loads without having it move from its original position…

I thank you in advance for any help you may have…