I have used the AEC tools to create a helical staircase but I can't see how to create a railing that follows the profile of the stairs.
If you select the stair, then right click, and from the context sensitive menu choose AEC -> Railing. To determine different parameters for the railing you can use AEC style manager to edit an existing railing style or create a new one.
Applies to:
Caddie 16 onwards