Perspective Grid: switch orientation on horizontal plane

I have a tall rectangle I want to place on the horizontal plane of the perspective grid.

Clicking that plane in the widget, or slecting the rectangle and hitting 2, results in the rectangle oriented towards the right vanishing point (or 2:00). I need it to point the other way, toward the left vanishing point (to 10:00).

Is there some way to force an object to do that?

Thanks for any help or thoughts on this.

Mark