You are very close.
Set all 4 rollers to the distance you want nice and equal/square. Now instead of moving it by hand to check your positioning, use the controls in repetier or the lcd screen. That will energize the steppers and lock them, and it will even return back to the initial position for you. The steppers should stay energized the whole time holing your rollers equal position.
This is assuming you are trying to square it then run it don the length of your work piece to ensure correct positioning.