;;----------------------replachr----------------------------
;; Params: oldchars: ordered list of single characters
;;         newchars: ordered list of characters &/or strings 
;;         instrg:   input string
;; Purpose: substitutes the corresponding element of newchars
;;          for every occurrence of each oldchar in instrg
;; Return: outstrg:  instrg modified as above
(defun replachr (oldchars newchars instrg / count flag ndex outstrg)
 (setq count 1
       outstrg "")
 (repeat (strlen instrg)
    (setq ndex 0 flag T)
    (repeat (length oldchars)
      (if (= (substr instrg count 1) (nth ndex oldchars))
      (setq outstrg (strcat outstrg (nth ndex newchars)) flag nil)
      );if
      (setq ndex (1+ ndex))
    );repeat
    (if flag (setq outstrg (strcat outstrg (substr instrg count 1))))
    (setq count (1+ count))
 );repeat
 outstrg
);replachr