cumulative addition macro edit

[tek9step]

Hi all i needed some help with the macro i am using which subtotal workbook & certain columns.. but what i want to be able to do is have a cummulative total instead of subtotals would that be possible.. regards

Public Sub InstallSubtotals()
Dim ws As Worksheet
Application.DisplayAlerts = False
Range("A3").Select
For Each ws In ActiveWorkbook.Worksheets
    If IsNumeric(ws.Name) Then
        With ws
            .UsedRange.RemoveSubtotal
            With .Range(.Cells(2, "C"), .Cells(.Rows.Count, "C").End(xlUp).Offset(, 24))
                .Subtotal GroupBy:=2, Function:=xlSum, _
                    TotalList:=Array(7, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21), _
                        Replace:=True, PageBreaks:=False, SummaryBelowData:=True
            End With
            .Outline.ShowLevels RowLevels:=2
            On Error Resume Next
            With .Cells(.Rows.Count, "D").End(xlUp).Resize(, 24)
                .SpecialCells(xlCellTypeBlanks).EntireColumn.Hidden = True
                .SpecialCells(xlCellTypeVisible).Borders(xlEdgeTop).Weight = xlThin
            End With
            On Error GoTo 0
            With .Range(.Cells(4, "D"), .Cells(.Rows.Count, "D").End(xlUp).Offset(, 23)).SpecialCells(xlCellTypeVisible)
                .Font.Bold = True
                .Borders(xlEdgeTop).Weight = xlThin
            End With
            .Columns("D:AA").Hidden = False
        End With
    End If