Specifying the VBScript file: Where can I specify the VBScript file that includes the functions I want to execute?

In GuiXT profile, lower right corner, there is an entry field "VBScript library" where you can specify the VBScript file, e.g. c:\vbscript\lib.vbs. In guixt.ini the parameter is VbsLibrary c:\vbscript\lib.vbs.