Extraire différence entre deux fichiers excel

Sub ExtractionDifférence()
    Application.ScreenUpdating = False
    Set f1 = ThisWorkbook
    
OuvrirFichier1:
    Fichier1 = Application.GetOpenFilename(filefilter:="tout,*.*", Title:="Sélection")
    If Fichier1 = False Then
        MsgBox "aucun fichier sélectionné", vbOKOnly + vbCritical, "fin de procédure "
        Exit Sub
    End If
    ThisWorkbook.FollowHyperlink Fichier1
    Fichier1 = ActiveWindow.Caption
    
OuvrirFichier2:
    Fichier2 = Application.GetOpenFilename(filefilter:="tout,*.*", Title:="Sélection")
    If Fichier2 = False Then
        MsgBox "aucun fichier sélectionné", vbOKOnly + vbCritical, "fin de procédure "
        Exit Sub
    End If
    If Fichier1 = Fichier2 Then
        MsgBox "Ce ficier est déjà ouvert"
        GoTo OuvrirFichier2
    End If
    ThisWorkbook.FollowHyperlink Fichier2
    Fichier2 = ActiveWindow.Caption
    
    f1.Activate
    Set F2 = Windows(Fichier1)
    Set F3 = Windows(Fichier2)
    ActiveSheet.AutoFilterMode = False
    Columns("A:C").ClearContents
    
    Set DicoF2 = CreateObject("Scripting.Dictionary")
    Set DicoF3 = CreateObject("Scripting.Dictionary")
    F2.Activate
    Sheets(1).Activate
    DerLigF2 = Sheets(1).Cells.Find("*", , , , xlByColumns, xlPrevious).Row
    DerColF2 = Sheets(1).Cells.Find("*", , , , xlByColumns, xlPrevious).Column
    For Each C In Range("A2:A" & DerLigF2)
        For i = 1 To DerColF2
            If Cells(C.Row, i) = "" Then ValCell = "£" Else ValCell = Cells(C.Row, i) & "£"
            X = X & ValCell
        Next i
        DebC = C
        C = X
        DicoF2.Add C, ""
        C = DebC
        X = ""
    Next C
Cdlt
    f1.Activate
    [A2].Resize(DicoF2.Count) = Application.Transpose(DicoF2.keys)

    F3.Activate
    Sheets(1).Activate
    DerLigF3 = Sheets(1).Cells.Find("*", , , , xlByColumns, xlPrevious).Row
    DerColF3 = Sheets(1).Cells.Find("*", , , , xlByColumns, xlPrevious).Column
    For Each C In Range("A2:A" & DerLigF3)
        For i = 1 To DerColF3
            If Cells(C.Row, i) = "" Then ValCell = "£" Else ValCell = Cells(C.Row, i) & "£"
            X = X & ValCell
        Next i
        DebC = C
        C = X
        DicoF3.Add C, ""
        C = DebC
        X = ""
    Next C
    f1.Activate
    [B2].Resize(DicoF3.Count) = Application.Transpose(DicoF3.keys)
    
    DerLigF1 = Application.WorksheetFunction.Max(DerLigF2, DerLigF3)
    Range("C2:C" & DerLigF1).FormulaR1C1 = "=IF(RC[-2]=RC[-1],"""",""Ecart"")"
    Range("A1") = Fichier1
    Range("B1") = Fichier2
    Range("C1") = "'Test"
    Columns("A:B").Select
    Selection.EntireColumn.AutoFit
    Selection.Replace What:="£", Replacement:="  ", LookAt:=xlPart
    For i = 1 To 10
        Cells.Replace What:="  ", Replacement:=" ", LookAt:=xlPart
    Next i
    Range("A1:C1").AutoFilter
    ActiveSheet.Range("A1:C" & DerLigF1).AutoFilter Field:=3, Criteria1:="Ecart"
End Sub