Copying mask without Scaling

Hello! I have autotraced a mask to a solid and am currently trying to paste this mask onto an mp4. The issue is the solid was scaled and when I copy the mask it tries to extent itself onto the mp4 instead of what I am trying to do which is to copy it to the same current position dispite the two layers having different things. Is there a way to pre compose just a mask? I can't pre compose the solid because when I autotrace that it traces the composition instead of its contents.