x = thisComp.width; y = thisComp.height; countX = 1;
xPos = -x * (timeToFrames() % countX);
yPos = -(timeToFrames() - (timeToFrames() % countX)) / countX * y;
transform.position = [xPos , yPos];
Sprite sheet animation player expression in After Effects. Very easy to use, just crop composition to the single frame and type sprite column count in "countX" variable. tutorial included in video.