Hi Peter,
Blumcraft is just one company that has a railglass system that fits the bill. See:
http://www.blumcraft.com/products/07182007/railglasssystems.php for their system.
Somewhere on their site they provide autocad files for all the members shown. There are at least two methods depending on the final use required:
For accuracy in the detail section: In AC-12 you can create a profile of this assembly, including the concrete or drywall or any other parts that form the stringer. Use the help files for the Profile Manager or do a search in Architalk, there have been many discussions resolved by use the Profile Manager. Note: check the "beam" under "use with" that way you can set it on an angle of your choosing to match the angle of the stair.
For 3D only or a design presentation, just use SEO's and then make the stair without hand rails, either through stairmaker, standard stairs or again the handy dandy Profile Manager.
In either case I would model the glass itself with SEO's (solid elem ops)
Cheers,
Mark
PS PM is this Menu: Design, Complex Profiles, Profile Manager.