<scripting> adding buttons to .ui form

The documentation shows how to load a “premade” .ui form, but is there a way to add widgets to it through scripting?

http://docs.toonboom.com/help/harmony-10.3/?utm_source=ohstgm&utm_medium=InSoftware&utm_campaign=HAR_10.3#HAR/Scripting/scripting__Introduction/000_CT_Scripting_Introduction.html%3FTocPath%3DScripting%20Guide|Toon%20Boom%20Harmony%2010.3%20Scripting%20Guide|_____1