Option Explicit

Public Sub ComputeAllSums()
   ComputeSums "Sheet1", "Sheet2"
End Sub

Public Sub ComputeSums(sMainSheet$, sSubSheet$)
   Dim lMainBankRow&, lSubBankRow&
   Dim sBank$
   Dim dblSum#
   
   On Error GoTo ErrHandle
   
   ' Åýñåóç ôùí ôñáðåæþí áðü ôï main sheet
   lMainBankRow = 1
   Do While ActiveWorkbook.Worksheets(sMainSheet).Cells(lMainBankRow, 1) <> ""
      sBank = ActiveWorkbook.Worksheets(sMainSheet).Cells(lMainBankRow, 1)
      
      ' Åýñåóç ôçò ôñÜðåæáò sBank óôï sub sheet êáé õðïëïãéóìüò áèñïßóìáôïò
      lSubBankRow = 1
      Do While ActiveWorkbook.Worksheets(sSubSheet).Cells(lSubBankRow, 1) <> sBank
         lSubBankRow = lSubBankRow + 1
      Loop
      lSubBankRow = lSubBankRow + 2   ' Ðçãáßíù óôçí 1ç ãñáììÞ ôçò ôñÜðåæáò ìå ôá ðïóÜ
      dblSum = 0
      Do While ActiveWorkbook.Worksheets(sSubSheet).Cells(lSubBankRow, 3) <> ""
         dblSum = dblSum + ActiveWorkbook.Worksheets(sSubSheet).Cells(lSubBankRow, 3)
         lSubBankRow = lSubBankRow + 1
      Loop
      
      ActiveWorkbook.Worksheets(sMainSheet).Cells(lMainBankRow, 2) = dblSum
   
      lMainBankRow = lMainBankRow + 1
   Loop
   
ToExit:
   Exit Sub
   
ErrHandle:
   MsgBox Err.Number & " - " & Err.Description, , "ERROR"
   Resume ToExit
End Sub