The following methods exposed via the cui Struct provide access to Custom User Interface (CUI) files.
cui.getDir() Returns the directory of the currently active CUI file as a string.
cui.getConfigFile() Returns the currently active CUI file name as a string.
cui.setConfigFile <filename_string> Sets the currently active CUI file to the specified file name.
cui.saveConfig() Saves the current CUI configuration data to the active .cui file
cui.saveConfigAs <filename_string> Saves current CUI configuration data to the specified file. The specified file is made the current CUI file.
cui.loadConfig <filename_string> Loads the CUI configuration data from supplied file. The specified file is made the current CUI file.
cui.loadConfig is only part of what needs to be done to switch over to a new UI scheme. The aforementioned macroScript will guide you through the other actions that also need to be performed.