If Cells(8, 29) <> 0 Then
        Cells(8, 30).Resize(77, 1) = Cells(8, 29).Resize(77, 1).Value
End If

Sub start()
  Dim countGlobal As Long
  Dim diff As Integer
  countGlobal = Cells(1, 12).Value
  For i = 1 To Cells(1, 8) / 50
    Cells(8, 23).Value = diff / 50
    diff = Cells(8, 22).Value
        For a = 1 To 50
            Cells(1, 12).Value = countGlobal + 1
            countGlobal = countGlobal + 1
            Cells(1, 10).Value = (i - 1) * 50 + a
            Cells(6, 4).Resize(1, 12) = Cells(7, 4).Resize(1, 12).Value
            Do Until Application.CalculationState = xlDone
            DoEvents
            Loop
            diff = diff + Cells(8, 22).Value
        Next
   Next
End Sub