This does not work:
(autoloader "C:\\Program Files\\ACAD2000\\LISP Routines\\SubRoutines\\test.lsp" '("ttt" ))
But this does
(autoloader "C:/Program Files/ACAD2000/LISP Routines/SubRoutines/test.lsp" '("ttt" ))
This fails to findfile
(autoloader "C:\\\\Program Files\\\\ACAD2000\\\\LISP Routines\\\\SubRoutines\\\\test.lsp" '("ttt" ))