It may not look pretty, But if you used strong enough Aluminum tubing or square stock.....ran a plate on the ceiling and grab the rafters as an Anchor point....you could accomplish your goal.
Another idea, would be to install a Angle piece in 2 corners of the shower. You should be able to grab something to screw to. Then fabricate a handhold running between the two corners.
Another idea, would be to install a Angle piece in 2 corners of the shower. You should be able to grab something to screw to. Then fabricate a handhold running between the two corners.
