How can I Improve this procedure...

Hi all,
 I have the following procedure in a service program that would be called
quite a few times from different programs.

How can I improve this procedure for performance? I am a little worried
about how the ReasonDS is declared.
Basically I need an Array of the Datastructure that the procedure can
return. I also need to be able to look up this array with @RsnCode as the
key.


* Array of Data structures to hold reason code details
D  ReasonDS       DS          5400
D   @RsnCode                     2A   Dim(200)
D   @Charge                      9  2 Dim(200)
D   @Weight                      9  0 Dim(200)
D   @Units                       7  0 Dim(200)


P BilUtil_getReasonTotals...
P                 B                   Export

D BilUtil_getReasonTotals...
D                 PI                  LikeDS(ReasonDS)
D @prPlant_                      3  0 Value
D @prBillTo_                     5  0 Value
D @prBillDate_                    D   Value
D @prInvoice_                    5  0 Value

 * Return Data structure
D tempReasonDS    DS                  LikeDS(ReasonDS)

 * Local variables
D @Count          S              2  0 Inz(*Zeros)
D @tCount         S              2  0 Inz(*Zeros)
D @Century        S              2  0 Inz(*Zeros)
D @BillDt         S              6  0 Inz(*Zeros)
 /free


   If Not %Open(BMCTOTL4);
      Open BMCTOTL4;
   EndIf;

   If Not %Open(BHCTOTL1);
      Open BHCTOTL1;
   EndIf;

   @Century = DateUtil_getCentury(@prBillDate_);
   @BillDt  = %Dec(%Char(@prBillDate_:*YMD0):6:0);

   // First check if record exists in current
   SetLL (@prPlant_:@prBillTo_:@prInvoice_:@Century:@BillDt) BMCTOTL4
   ReadE (@prPlant_:@prBillTo_:@prInvoice_:@Century:@BillDt) BMCTOTL4
   DoW Not %EoF(BMCTOTL4);
         // Accumulate all charges per reason code for this custom
         @tCount = %LookUp(BTREA:@RsnCode);
         If @tCount <> 0;
            tempReasonDS.@Charge(@tCount) += BTTDO;
            tempReasonDS.@Weight(@tCount) += BTTLB;
            tempReasonDS.@Units(@tCount)  += BTTUN;
         Else;
            @Count += 1;
            tempReasonDS.@RsnCode(@Count) = BTREA;
            tempReasonDS.@Charge(@Count)  = BTTDO;
            tempReasonDS.@Weight(@Count)  = BTTLB;
            tempReasonDS.@Units(@Count)   = BTTUN;

EndIf;


         ReadE (@prPlant_:@prBillTo_:@prInvoice_:@Century:@BillDt)
                          BMCTOTL4;
   EndDo;