AutoLISP (LSP or MNL) files contain programs
that add custom commands and functions which can be used as part
of the user interface. You can load AutoLISP files into a CUIx file
using the Customize tab of the Customize User Interface (CUI) Editor.
more information about using AutoLISP, see
AutoLISP and Visual LISP.
files with the same name and location as your main, enterprise,
or partial CUIx files are loaded automatically. These files cannot
be unloaded once loaded into AutoCAD.
To load an AutoLISP
file in the Customize User Interface Editor