Different idea, bear with me if I don't get it across right. Take a pipe(larger diamiter) and mount it on the outside next to the door opening, have it long enough to reach from the floor up to the tub lip. Now take a smaller diamiter pipe that will slide into the mounted base and extend up the door frame halfway( you'll have to measure your wife to decide the right height). Take more of the smaller pipe and weld it up to the long pole in the shape of a 4. Drill holes through the base and the insert and put pins in to stop the bar from twisting. The rail can be lifted out by pulling the pins and it can be stored in the pup for travel and installed at set up.