IDENTIFICATION DIVISION.
       PROGRAM-ID. "RE-ESCAPE".

       DATA DIVISION.
       WORKING-STORAGE SECTION.
       01 ESCAPED PIC X(999).
       01 PTRS.
           03 IN-PTR PIC 999.
           03 OUT-PTR PIC 999.
       01 CURRENT-CHAR PIC X.
           88 ESCAPE-CHAR VALUE "$".
       01 LOOP-STATE PIC 99.
           88 DONE VALUE 99.

       LINKAGE SECTION.
       01 BUFFER PIC X(999).

       PROCEDURE DIVISION USING BUFFER.
           MOVE 0 TO LOOP-STATE.
           MOVE 1 TO IN-PTR, OUT-PTR.
           MOVE SPACES TO ESCAPED.
           PERFORM MAYBE-ESCAPE-CHAR UNTIL DONE.
           MOVE ESCAPED TO BUFFER.
           EXIT PROGRAM.

       MAYBE-ESCAPE-CHAR.
           IF IN-PTR IS LESS THAN 999 AND
              OUT-PTR IS LESS THAN 999 THEN
               UNSTRING BUFFER INTO CURRENT-CHAR WITH POINTER IN-PTR
               IF ESCAPE-CHAR THEN
                   IF OUT-PTR IS LESS THAN 998 THEN
                       STRING "$$" INTO ESCAPED WITH POINTER OUT-PTR
                   ELSE MOVE 99 TO LOOP-STATE
               ELSE
                   STRING CURRENT-CHAR INTO ESCAPED WITH POINTER OUT-PTR
           ELSE
               MOVE 99 TO LOOP-STATE.