The only solution for your problem is to select the stair railing, edit and draw it along the balcony where plans to the other railing.
example: I have in the first level a ladder reaching to the second level. I select the second level and edited the railing, I select in editing and drawing tools to create a continuation of the handrail.
Please see attached image
Regards,
Alexis Catalán
CAD/BIM Administrator