The rod just gives you an option for raising up one end of the wood. You could place a wedge under the wood or arrange a way to raise up the bar and hold it. Thinking on it, just make a sled with two boards, hinged at the end. The wedge can then go between the boards while the wood sits flush on the upper board (lower hinge pin end goes into the planer first).
Crude drawing with exaggerated hole at an angle: The bottom board rides on the planer or drum sander bed
