(defun C:MEXT(/ b e p l c)                    ;define function
 (setvar "CMDECHO" 0)                         ;turn off command echo
 (setq c -1)                                  ;set counter
 (prompt "Select boundary edge(s)...")        ;Prompt user
 (setq b (ssget))(terpri)(terpri)             ;"b" = boundary edges
 (prompt "Select object(s) to extend...")     ;Prompt user
 (setq e (ssget))(terpri)(terpri)             ;"e" = entities to extend
 (setq l (sslength e))                        ;"l" = number of entities in "e"
 (setq p (getpoint "Pick side to extend...")) ;"p" = reference point for extend
 (command "EXTEND" b "")                      ;EXTEND command, get boundaries
 (repeat l                                    ;start loop
  (setq c (1+ c))                             ;set counter
  (command (list (ssname e c) p))             ;continue extend command using 
 )                                            ;  each item in "e"
 (command "")                                 ;end EXTEND command  
 (setvar "CMDECHO" 1)                         ;turn command echo back on
 (prin1)                                      ;quiet exit
)                                             ;close function