SUBROUTINE RVSNAM(KFILDO,EQNNAM,NPROJ,IER)
C
C        JANUARY   2015   GLAHN   MDL   MOS-2000
C        MAY       2015   GLAHN   REVISED TO ADD UP TO 3 DIGITS VICE 2
C
C        PURPOSE
C            TO MODIFY THE FILE NAME IN EQNNAM.  IT IS THE FILE
C            CONTAINING THE REGRESSION EQUATIONS.  IT IS UP TO 
C            60 CHARACTERS IN LENGTH, AND MUST END IN ONE, TWO, OR
C            THREE NUMERIC DIGITS.  THESE DIGITS ARE REPLACED WITH THE
C            FORECAST PROJECTION NPROJ.
C   
C        DATA SET USE
C            KFILDO    - UNIT NUMBER OF OUTPUT (PRINT) FILE.  (OUTPUT)
C
C        VARIABLES
C              KFILDO = UNIT NUMBER OF OUTPUT (PRINT) FILE.  (INPUT)
C              EQNNAM = NAME OF FILE  TO BE MODIFIED.  (INPUT/OUTPUT)
C               NPROJ = FORECAST PROJECTION.  (INPUT)
C                 IER = COMPLETION CODE.  (OUTPUT)
C                         0 = GOOD
C                       777 = ERROR.  WILL BE TREATED AS FATAL IN
C                             CALLING PROGRAM.
C        1         2         3         4         5         6         7 X
C
C        NONSYSTEM SUBROUTINES USED 
C            NONE
C
      CHARACTER*60 EQNNAM
C
D     CALL TIMPR(KFILDO,KFILDO,'START RVSNAM        ')
      IER=0
C
CCC      WRITE(KFILDO,100)EQNNAM
CCC 100  FORMAT(/' EQUATION FILE NAME = ',A60)
C
      DO 110 J=60,3,-1
C
      IF(EQNNAM(J:J).EQ.' ')THEN
         GO TO 110
      ELSE
C
C           TEST TWO CHARACTERS FOR NUMERIC VALUE.
C
         IF(EQNNAM(J:J).GE.'0'.AND.
     1      EQNNAM(J:J).LE.'9')THEN
C              NUMERIC VALUES 46-57 ARE THE DIGITS 0 THROUGH 9.
C
            IF(EQNNAM(J-1:J-1).GE.'0'.AND.
     1         EQNNAM(J-1:J-1).LE.'9')THEN
C
               IF(EQNNAM(J-2:J-2).GE.'0'.AND.
     1            EQNNAM(J-2:J-2).LE.'9')THEN
                  NPLACE=J-2
               ELSE
                  NPLACE=J-1
               ENDIF
C               
            ELSE
               NPLACE=J
            ENDIF
C
            GO TO 115
         ELSE
            WRITE(KFILDO,105)
 105        FORMAT(/' ****FILE NAME IN RVSNAM DOES NOT END IN',
     1              ' A NUMERIC VALUE.  ABORT AT 105.')
            IER=777
            GO TO 150
         ENDIF
C
      ENDIF
c
         WRITE(KFILDO,106)
 106     FORMAT(/' ****FILE NAME IN RVSNAM DOES NOT END IN',
     1           ' A NUMERIC VALUE OR IS LESS THAN 3 CHARACTERS',
     2           ' IN LENGTH.  ABORT AT 106.')
         IER=777
         GO TO 150
C
 110  CONTINUE
C
C        THE PLACEMENT OF THE PROJECTION STARTS IN LOCATION NPLACE IN 
C        EQNNAM.
C
 115  IF(NPROJ.GE.100)THEN
         NOPL=3
C           THREE DIGITS MUST BE PLACED.
C
         IF(NPLACE.GT.58)THEN
            WRITE(KFILDO 116)
 116        FORMAT(/' ****NOT ROOM FOR PROJECTION OF 3 CHARACTERS IN',
     1              ' FILE NAME.  ABORT IN RVSNAM AT 116.')
            IER=777
            GO TO 150
         ENDIF
C         
      ELSEIF(NPROJ.GE.10)THEN
         NOPL=2
C           TWO DIGITS MUST BE PLACED.
C 
         IF(NPLACE.GT.59)THEN
            WRITE(KFILDO,120)
 120        FORMAT(/' ****NOT ROOM FOR PROJECTION OF 2 CHARACTERS IN',
     1              ' FILE NAME.  ABORT IN RVSNAM AT 120.')
            IER=777
            GO TO 150
         ENDIF
C
      ELSE
         NOPL=1
C           PLACE ONE DIGIT.
      ENDIF  
C
C        NOW DO THE PLACEMENT, NOPL CHARACTERS STARTING IN NPLACE.
C
D     WRITE(KFILDO,125)NOPL,NPLACE
D125  FORMAT(/' AT 125 IN RVSNAM--NOPL,NPLACE',2I4)
C
      IF(LPLACE+NOPL-1.GT.60)THEN
         WRITE(KFILDO,127)NOPL,NPLACE
 127     FORMAT(/' ****NOT ROOM TO PLACE',I4,' DIGITS STARTING IN',
     1           ' POSITION',I4,'.  PLACEMENT NOT MADE.')
         IER=777
         GO TO 150
      ENDIF
C
      IF(NOPL.EQ.1)THEN
C
         IF(NPLACE.EQ.60)THEN
            WRITE(EQNNAM(NPLACE:NPLACE),130,IOSTAT=IOS,ERR=138)NPROJ
 130        FORMAT(I1)
         ELSEIF(NPLACE.EQ.59)THEN
C              THIS GUARDS AGAINST 2 DIGITS BEING REPLACED BY 1 AND
C              THE SECOND BEING LEFT.
            WRITE(EQNNAM(NPLACE:NPLACE+1),131,IOSTAT=IOS,ERR=138)NPROJ
 131        FORMAT(I1,' ')
         ELSE
            WRITE(EQNNAM(NPLACE:NPLACE+2),132,IOSTAT=IOS,ERR=138)NPROJ
 132        FORMAT(I1,'  ')
         
         ENDIF
C
      ELSEIF(NOPL.EQ.2)THEN
C
         IF(NPLACE.EQ.59)THEN
            WRITE(EQNNAM(NPLACE:NPLACE+1),133,IOSTAT=IOS,ERR=138)NPROJ
 133        FORMAT(I2)
         ELSE
            WRITE(EQNNAM(NPLACE:NPLACE+2),135,IOSTAT=IOS,ERR=138)NPROJ
 135        FORMAT(I2,' ')
         ENDIF
C
      ELSE
         WRITE(EQNNAM(NPLACE:NPLACE+2),136,IOSTAT=IOS,ERR=138)NPROJ
 136     FORMAT(I3)
      ENDIF     
C
      GO TO 150 
C
 138  WRITE(KFILDO,139)IOS
 139  FORMAT(/' ****ERROR ON INTERNAL WRITE IN RVSNAM AT 139',
     1        '  IOSTAT=',I5,'.  ABORT.')
      IER=777
C
 150  WRITE(KFILDO,151)EQNNAM
 151  FORMAT(' COMPUTED FILE NAME = ',A60)
C
 200  CONTINUE
C
D     CALL TIMPR(KFILDO,KFILDO,'END RVSNAM          ')
      RETURN
      END