Well I got further with it.
this only allows you to pick 2 points for your mline.
Code:
(defun c:ddcf ()
(setq currlay (getvar "clayer"))
(setq scale (getdist "Scale: "))
(SETQ lr1 (TBLSEARCH "LAYER" "MLINE"))
(IF (= LR1 NIL)
(COMMAND "LAYER" "MAKE" "MLINE" "COLOR" "4" "" ""))
(command "layer" "set" "mline" "" "")
(command "mline" "scale" scale "style" "" pause pause pause "")
(command "explode" (entlast) "")
(setvar "clayer" currlay)
(princ))
I'll look into being able to pick more points.
Are you going to close it like a polyline?
I'll bet there's gurus out there who can improve on it!