I know how to script global settings,

I found it quite easy to add global settings to the MVO when I am controlling specific parts(those with clearly defined macros or no macros at all) or custom made parts, but the stair gdl has me a little lost.

What I don't know is what parts I need to edit specifically for the stairs.

Example: when you "Create a Stair", what parts does it pull from to create this stair? When a stair has been created there is no gdl associated to it AFAIK (visible anyway), when you select a stair and open the object all you get is the GUI screen for that stair (no GDL).

When you search within the AC13 Library for the individual stair parts that would create the composite stair (BTW, I don't use the default Library, I have extracted the Library to customize many different parts for our office) there are literally 65+ individual gsm parts to choose from:
-03 40 00 Precast (4 parts)
-05 51 00 Metal Stairs (4 parts)
-05 52 00 Metal Railings (7 parts)
-06 43 00 Wood Stairs and Railings (23 parts)
-MACROS 13_Structure Macros_Railing Macros & Stair Macros (29 parts)

Example: when you "Create a Stair"

You are talking about StairMaker's stair?

If Yes ...

I think you are going to a closed way.
Do you know that StairMaker use Vert Edge and Pgon to create the body?
Use a txt files for railing (inside AddOns>StairMaker>Railings)
Do you know StairMaker doesn't use nobody macro from the library?

If StairMaker uses some macro, I think arrives from an embedded library (inside apx) and you can not change it.

If No

I don't know where is the problem??
You have to made :
1)Your own UI interface objects. You can see it into Model View Options.
2)And add in your (stair) object the global code
This is all

Thank you CU mirco.

I did not know how Stairmaker created stairs. I assumed the Stairmaker GUI was linked to a macro or macros.

It sounds like I will not be able to control a custom stair (from Stairmaker) w/ Model View Options.