Involute profile in autocad

I'm looking a highly accurate way to draw the involute. Any suggestion?
I'm using AutoCad 2004. In the past in AutoCad 12 I used a nice LISP program IMPORT-3D-POLY written by Tony Hotchkiss, 2003 program which has converted from Excell Spreadhseet the involute cordinates into polyline in Autocad. Right now when I try to do same in Acad 2004, i always have a message:

IMPORT-3D-POLY - Error: bad argument type: FILE nil

what's the problem?

The lsp program looks like this:

;;; Cadalyst April 2003 AutoLISP Solutions
;;; import-3d-poly.lsp imports x,y,z coordinates
;;; from Excel spreadsheet into AutoCAD.
;;; Program (c) Tony Hotchkiss, 2003
;;;
(defun err (s)
(if (= s "Function cancelled")
(princ "IMPORT-3D-POLY - cancelled: ")
(progn (princ "IMPORT-3D-POLY - Error: ")
(princ s)
(terpri)
) ;_ progn
) ; if
(resetting)
(princ "SYSTEM VARIABLES have been reset\n")
(princ)
) ; err
(defun setv (systvar newval)
(setq x (read (strcat systvar "1")))
(set x (getvar systvar))
(setvar systvar newval)
) ; setv
(defun setting ()
(setq oerr *error*)
(setq *error* err)
(setv "CMDECHO" 0)
(setv "BLIPMODE" 0)
) ; end of setting
(defun rsetv (systvar)
(setq x (read (strcat systvar "1")))
(setvar systvar (eval x))
) ; restv
(defun resetting ()
(rsetv "CMDECHO")
(rsetv "BLIPMODE")
(setq *error* oerr)
) ; end of resetting

(defun poly3D ()
(setq ptlist1 (get-ptlist))
(make-3dpolyline ptlist1)
) ;_ poly3D

(defun get-ptlist ()
(setq fn (getfiled "3D points file" "" "txt" 8)
f (open fn "r")
str (read-line f)
plist nil
) ;_ end of setq
(while (/= str EOF)
(setq str (read-line f))
(if str
(progn
(setq pt (get-pt str))
(setq plist (append plist (list pt)))
) ;_ end of progn
) ;_ end of if
) ;_ end of while
(setq f (close f))
plist
) ;_ get-ptlist

(defun get-pt (str1)
(setq comma (chr 44)
str2 ""
count 1
i 0
) ;_ end of setq
(repeat 2
(repeat (strlen str1)
(setq char (substr str1 (setq i (1+ i)) 1))
(if (/= char comma)
(setq str2 (strcat str2 char))
(progn
(if (= count 1)
(progn
(setq x (atof str2))
(setq str1 (substr str1 (1+ i)))
(setq i 0)
(setq count 2)
(setq str2 "")
) ;_ end of progn
(progn
(setq y (atof str2))
(setq str1 (substr str1 (1+ i)))
(setq z (atof str1))
) ;_ end of progn
) ;_ end of if
) ;_ end of progn
) ;_ end of if
) ;_ end of repeat
) ;_ end of repeat
(setq pt (list x y z))
) ;_ end of get-pt

(defun make-3dpolyline (ptlist)
(entmake (list '(0 . "POLYLINE")
'(100 . "AcDbEntity")
'(100 . "AcDb3dPolyline")
'(70 . 8)
) ;_ list
) ;_ entmake
(repeat (length ptlist)
(setq pt (car ptlist)
ptlist (cdr ptlist)
) ;_ setq
(entmake (list '(0 . "VERTEX")
'(100 . "AcDb3dPolylineVertex")
(cons 10 pt)
'(70 . 32)
) ;_ list
) ;_ entmake
) ;_ repeat
(entmake '((0 . "SEQEND")))
) ;_ make-3dpolyline

(defun cl3 ()
(setting)
(poly3D)
(resetting)
(princ)
) ;_ cl3

(prompt "Enter PL3 to start")