With Advance Steel 2018, you can now create a wall rail on concrete.
The wall rail tool is located on the Extended Modeling tab, Structural Elements panel. This video will show how to accomplish this.
Simply move the UCS to the face of the concrete, position the orientation of the X and Y axis accordingly, use the view on UCS tool and turn on your 2d snaps located on the Quick views category of the Advance steel tool Palette.
Create a line where you want the wall rail to be. In this video the system line of the stringer and landing was used.
Use the wall rail tool to create and customize the rail. Tweak the railing using the options located on the General, Wall Plates, Connections and Rail Segments panels. You can then save the customized railing in the library located on the Properties panel for later use.