This is the final version of my graph based on @Steven and @awilliams code above (thanks both). I won’t try to figure out the direction of rotation so I added an option to select it ( usually the smaller rotation is the right direction).
Inputs are the Elevation Mark to rotate, the wall to look at and the elevation that will look at that wall (and the direction of rotation clockwise or not).
rotate elevations to look at wall.dyn (28.4 KB)