So I'm building a three level house, and the owner wants a partially open stairway. What they're looking for is something like the attached picture. What I need to do is attach a kind of "cap" on the walls bounding the staircase, then add the same rail going down it to the main level floor. Whatever I try to do gets warped. It either wants to go to the stairs, or attach as a handrail to the side of the wall.
How can I cap the walls, and get the railing to follow along with the slope?