carmen:
If the 2D Script is empty, then ArchiCAD will use the drawing elements (lines, fills, hotspots) in the 2D Symbol window for the 2D symbol of the part. If the 2D Script is used, then the contents of the 2D Symbol window will be ignored, unless called by a FRAGMENT2 statement. 2D drawings tend to be much less sophisticated than what can be accomplished via scripting.
I opened one of the ArchiCAD 12 library windows (W Awning 1 12) and indeed, the 2D Script is empty (as are all the other Script windows except the Master Script), in the Master Script window, a Call is made to a macro (gs_general_w_macro_USA) where the various scripts reside. So editing one of these windows really means editing this macro, which would change any window using this macro.
You should add a Signature to your Profile (click the Profile button near the top of this page) with your ArchiCAD version and operating system (see mine for an example) for more accurate help in this forum.
David