Using single letter commands inside AutoCAD will save you
substantial amounts of time. Here is the trick I learned to
accomplish this, and it uses no memory.

(defun c:L ()
  (command "line")
)

This simple lisp routine can be created on any word
processing package that can save in ascii format. You can
also string together many of your most used commands into
single letter ease.

Just name your file anything that you wish and simply load at
after acad.lsp is loaded at drawing startup.

Hope this trick works for you as it does for me.