Creating Polyline from Points

(vl-load-com)
 ;;; to make a 3d polyline*******************************************
 (defun c:pol (/ adoc spc ss cnt plst 3dline)
 (setq adoc(vla-get-activedocument(vlax-get-acad-object)))
 (setq spc(vlax-get adoc
 (if (equal (getvar "cvport") 1)
 'PaperSpace
 'ModelSpace
 );_if
 )
 );_setq
 (setq ss (ssget '((0 . "POINT"))));_select only point objects
 (if ss
 (progn
 (setq cnt 0);_loop counter
 (setq plst '());_empty list
   (while (< cnt (sslength ss))
 (setq plst (cons(cdr(assoc 10(entget (ssname ss cnt))))plst));_make point list
 (setq cnt (1+ cnt));_incerase counter
     );_while
 (setq 3dline (vla-add3dpoly ;_make 3d polyline
       spc
       (vlax-safearray-fill
  (vlax-make-safearray vlax-vbDouble
  (cons 0 (1- (length (apply 'append plst)))))
  (apply 'append plst)))
       );_setq add 3dpoly
 );_progn
 );_if
 (princ)
   );_defun
 ;;; to make a 3d  spline******************************************
 (defun c:spl (/ adoc spc ss cnt plst 3dline stpt ept)
 (setq adoc(vla-get-activedocument(vlax-get-acad-object)))
 (setq spc(vlax-get adoc
 (if (equal (getvar "cvport") 1)
 'PaperSpace
 'ModelSpace
 );_if
 )
 );_setq
 (setq ss (ssget '((0 . "POINT"))))
 (if ss
 (progn
 (setq cnt 0);_loop counter
 (setq plst '());_empty list
   (while (< cnt (sslength ss))
 (setq plst (cons(cdr(assoc 10(entget (ssname ss cnt))))plst))
 (setq cnt (1+ cnt));_incerase counter
     );_while
 (setq stpt (vlax-3d-point '(0.0 0.0 0.0)));_start pt for spline
 (setq ept (vlax-3d-point '(0.0 0.0 0.0)));_end pt for spline
 (setq cline (vla-addspline
       spc
       (vlax-safearray-fill
  (vlax-make-safearray vlax-vbDouble
  (cons 0 (1- (length (apply 'append plst)))))
  (apply 'append plst))
       stpt
       ept
       )
       );_setq add 3d spline
 );_progn
 );_if
 (princ)
   );_defun