Question sur une macro VBA Excel

Bonjour à toutes et à tous,

en surfant sur la toile, j'ai trouvé une macro très utile pour mon travail, que j'ai au préalable légèrement modifié:

Sub CompareWorksheets(ws1 As Worksheet, ws2 As Worksheet)
Dim r As Long, c As Integer
Dim lr1 As Long, lr2 As Long, lc1 As Integer, lc2 As Integer
Dim maxR As Long, maxC As Integer, cf1 As String, cf2 As String
Dim rptWB As Workbook, DiffCount As Long
    Application.ScreenUpdating = False
    Application.StatusBar = "Creating the report..."
    Set rptWB = Workbooks.Add
    Application.DisplayAlerts = False
    While Worksheets.Count > 1
        Worksheets(2).Delete
    Wend
    Application.DisplayAlerts = True
    With ws1.UsedRange
        lr1 = .Rows.Count
        lc1 = .Columns.Count
    End With
    With ws2.UsedRange
        lr2 = .Rows.Count
        lc2 = .Columns.Count
    End With
    maxR = lr1
    maxC = lc1
    If maxR < lr2 Then maxR = lr2
    If maxC < lc2 Then maxC = lc2
    DiffCount = 0
    For c = 1 To maxC
        Application.StatusBar = "Comparing cells " & Format(c / maxC, "0 %") & "..."
        For r = 1 To maxR
            cf1 = ""
            cf2 = ""
            On Error Resume Next
            cf1 = ws1.Cells(r, c).FormulaLocal
            cf2 = ws2.Cells(r, c).FormulaLocal
            On Error GoTo 0
            If cf1 <> cf2 Then
                DiffCount = DiffCount + 1
                Cells(r, c).Formula = "'" & cf1 & " <> " & cf2
            End If
        Next r
    Next c
    Application.StatusBar = "Formatting the report..."
    With Range(Cells(1, 1), Cells(maxR, maxC))
        .Interior.ColorIndex = 19
        With .Borders(xlEdgeTop)
            .LineStyle = xlContinuous
            .Weight = xlHairline
        End With
        With .Borders(xlEdgeRight)
            .LineStyle = xlContinuous
            .Weight = xlHairline
        End With
        With .Borders(xlEdgeLeft)
            .LineStyle = xlContinuous
            .Weight = xlHairline
        End With
        With .Borders(xlEdgeBottom)
            .LineStyle = xlContinuous
            .Weight = xlHairline
        End With
        On Error Resume Next
        With .Borders(xlInsideHorizontal)
            .LineStyle = xlContinuous
            .Weight = xlHairline
        End With
        With .Borders(xlInsideVertical)
            .LineStyle = xlContinuous
            .Weight = xlHairline
        End With
        On Error GoTo 0
    End With
    Columns("A:IV").ColumnWidth = 20
    rptWB.Saved = True
    If DiffCount = 0 Then
        rptWB.Close False
    End If
    Set rptWB = Nothing
    Application.StatusBar = False
    Application.ScreenUpdating = True
    MsgBox DiffCount & " cells contain different formulas!", vbInformation, _
        "Compare " & ws1.Name & " with " & ws2.Name
End Sub
Sub ApplyCompareWorksheets()
    ' compare two different worksheets in two different workbooks
    CompareWorksheets ActiveWorkbook.Worksheets("Sales Master"), _
        Workbooks("Discount Matrix April 2011 - Copie.xls").Worksheets("Sales Master")
End Sub 

Cependant, j'aimerais pouvoir effectuer plusieurs modifications, comme par exemple afficher la cellule en rouge s'il y a bien une différence.
Mes capacités en codage sont très limitées...
Merci d'avance!