CorelDRAW Graphics Suite X5 :: Adjust Perspective Effect Using Arrow Keys?

Is there some way to move the corner control points of the perspective effect grid via the arrow keys? I have hand problems and any time I need to move something very precisely I use the arrow keys, or risk hurting my hands. If not, would there be some way to do this with a macro? Also, is there some setting for it – other than having to hold down the shift and control keys while you click and drag, which is just a killer for me – that will arrange it in ways that are only symmetrical (where if you move one side the other side moves equally in the opposite direction)? As far as I can see, rectangular and freehand settings behave the same.