Calls IDMSCALC to get target page for given page range and key. IDMS loadlib must be in loadlib search chain or you need to copy IDMSCALC to a loadlib that is. Don't worry about IDMSCALC changing - this is one routine that can't (think about it).

The panel is not shown here. Both routines are in the downloadable sample zip.

/* REXX */
trace off

/**********************************************************************/
/*   Initialisation                                                   */
/**********************************************************************/
Msg    = ""
Lo     = ""
Hi     = ""
Len    = ""
Key    = ""
KeyH   = " "
PKey   = " "
Target = ""

/**********************************************************************/
/*   Main processing loop                                             */
/**********************************************************************/
DO forever
   "ISPEXEC DISPLAY PANEL (@MGPCALC"
   IF rc = 8 then leave
   Msg = ""
   IF Lo   = 0               then Msg = Msg "**Lo**"
   IF Hi   = 0               then Msg = Msg "**Hi**"
   IF Hi   ¬> Lo             then Msg = Msg "**Lo/Hi**"
   IF Len  = 0   ³ Len > 256 then Msg = Msg "**Len**"
   IF Msg  ¬= "" then iterate
   PTarget = D2C(0,4)
   PHi     = D2C(Hi,4)
   PLo     = D2C(Lo,4)
   PLen    = D2C(Len,2)

   IF KeyH ¬= C2X(PKey) & length(KeyH) > 0 then do
      call HexKey
      Key  = ""
   end
   ELSE do
      PKey = substr(Key,1,Len," ")
      KeyH = C2X(PKey)
   end
   IF Msg ¬= "" then iterate

   Parm    = PTarget³³PHi³³PLo³³PLen³³PKey
   address linkpgm "IDMSCALC Parm"

   Target = C2D(substr(Parm,1,4),4)
end

exit

HexKey:
IF Len ¬= length(KeyH) / 2 then do
   Msg = "**HEX length**"
   return
end
PKey = ""

DO i = 1 to length(KeyH) by 2
   HexHi = substr(KeyH,i,1)
   HexLo = substr(KeyH,i+1,1)
   call ValHex
   PKey = Pkey³³D2C(HexVal,1)
end

return

ValHex:
HexVal = 0
HiNum = 256
IF HexHi = "0" then HiNum = 0
IF HexHi = "1" then HiNum = 16
IF HexHi = "2" then HiNum = 32
IF HexHi = "3" then HiNum = 48
IF HexHi = "4" then HiNum = 64
IF HexHi = "5" then HiNum = 80
IF HexHi = "6" then HiNum = 96
IF HexHi = "7" then HiNum = 112
IF HexHi = "8" then HiNum = 128
IF HexHi = "9" then HiNum = 144
IF HexHi = "A" then HiNum = 160
IF HexHi = "B" then HiNum = 176
IF HexHi = "C" then HiNum = 192
IF HexHi = "D" then HiNum = 208
IF HexHi = "E" then HiNum = 224
IF HexHi = "F" then HiNum = 240
LoNum = 256
IF HexLo = "0" then LoNum = 0
IF HexLo = "1" then LoNum = 1
IF HexLo = "2" then LoNum = 2
IF HexLo = "3" then LoNum = 3
IF HexLo = "4" then LoNum = 4
IF HexLo = "5" then LoNum = 5
IF HexLo = "6" then LoNum = 6
IF HexLo = "7" then LoNum = 7
IF HexLo = "8" then LoNum = 8
IF HexLo = "9" then LoNum = 9
IF HexLo = "A" then LoNum = 10
IF HexLo = "B" then LoNum = 11
IF HexLo = "C" then LoNum = 12
IF HexLo = "D" then LoNum = 13
IF HexLo = "E" then LoNum = 14
IF HexLo = "F" then LoNum = 15
IF HiNum = 256 ³ LoNum = 256 then do
   Msg = "**Not HEX**"
   return
end
HexVal = HiNum + LoNum
return