The answer to my question is 'Startup.lsp'. Found it doing Google searches.

We are considering replacing AutoCAD with DraftSight Pro. We have a couple of hundred AutoLISP programs that need to work in DraftSight. I have been able to import the custom toolbars and they display fine, but of course they don’t work because the LISP files are not loaded.

In AutoCAD if ‘ACAD.LSP’ is placed in the support directory it automatically loads on startup. Is there a LISP filename that will automatically load if placed appreciate directory in DraftSight? If so, I should be able to rename the file and place it in the appreciate directory and it should load automatically on startup.