Image Ready Help Please

I'm trying to do a minimovie in IR. I've got the "movie" down to 31x38px and under 35k and saved as an animated gif. Now I just want to put it onto a base but I can't work out how to do it. I've followed some other instructions about changing the canvas dimensions to 100x100. The gif goes to the top right hand corner which is not exactly where I want it. I want it about 20px down and 10px to the left but I can't work out how to move it there. Can somebody please help me?