LISP to copy Polylines with certain points fixed (kind of strech-copy)

Hello,

after reading along for quite some time (and profiting alot), here comes my first post:

I needed a routine to create a lot of polylines with all the same starting point. I got tired of always have to move the first point back to the right starting point.

Here is my solution, kind of an copy-strech mix. Could this be achieved in a more elegant way?

(defun c:cfp ( / i ss plist_o ss_n elist_t plist_t pcount bpoint) 

(vl-load-com)

 ;get points of original polyline

(setq 
   ss (car(entsel "\nSelect Polyline to copy.")) 
   plist_o (vl-remove-if-not
     (function (lambda (pt) (= (car pt) 10)))
     (entget ss)
             )
)

 ;get userinput on how many points should be fixed and basepoint for multiple copies
 
(initget 4)
(setq 
 pcount (getint "\nHow many points should be fixed? <1>"))
 (if (= pcount nil) (setq pcount 1)) 
 (setq bpoint (getpoint "\nSelect basepoint"))
 (while (not nil)

 ;perform copy and get the points of the temporal polyline
 
(command "_copy" ss "" bpoint pause)

 (setq 
   ss_n (entlast)
   elist_t (entget ss_n)
   plist_t (vl-remove-if-not
               (function (lambda (pt) (= (car pt) 10)))
               (entget ss_n)
            )
  )

 ;change the fixed points of the temporal polyline back to the 
 ;original points and draw the final polyline
 
(setq i 0)
(repeat pcount
   (setq elist_t
     (subst
       (nth i plist_o)
       (nth i plist_t)
       elist_t
     )
  )
  (setq i (1+ i))
)
 
(entmod elist_t)
 )
)