VBA Excel: Ajouter une colonne à tous les fichiers du dossier

Option Explicit

Private Const CHEMIN = "C:\MonDossier\" 'Mettre le chemin du dossier contenant les fichiers

Sub AjouterColonne()
Dim mTabFile()
Dim i As Long
Dim wb As Workbook
Dim ws As Worksheet
    
    Application.ScreenUpdating = False
    Application.DisplayAlerts = False
    
    'Récupération des fichiers
    Call RecupFichier(mTabFile)
    
    'Boucle sur tous les fichiers
    For i = LBound(mTabFile()) To UBound(mTabFile())
        Set wb = Workbooks.Open(mTabFile(i))
        '*** /!\ Modifier la ligne suivante pour l'adapter à la feuille à modifier
        Set ws = wb.Sheets(1)
        
        'Insertion d'une colonne avant la colonne C
        ws.Columns("C:C").Insert Shift:=xlToRight, CopyOrigin:=xlFormatFromLeftOrAbove
        'Titre de la colonne C "Date"
        ws.Range("C1").Value = "Date"
        'Sauvegarde du fichier et libération des objets
        wb.Save
        Set ws = Nothing
        wb.Close
        Set wb = Nothing
    Next i
    
    Application.ScreenUpdating = True
    Application.DisplayAlerts = True
    
End Sub

Private Sub RecupFichier(ByRef mTab)
Dim myFile As String
Dim ind As Long

    myFile = Dir(CHEMIN & "*.xlsx")
    
    Do While Len(myFile) > 0
        ReDim Preserve mTab(ind)
            mTab(ind) = CHEMIN & myFile
        myFile = Dir()
    Loop
    
End Sub

Sub Ajout_ColonneB()
Dim wbbase As Workbook
Dim ext As String, chemin As String
Dim fs As Object, f As Object, sf As Object
Dim wbo As Variant
Application.ScreenUpdating = False
Set wbbase = ActiveWorkbook
chemin = wbbase.Path
ext = "xlsx"
Set fs = CreateObject("Scripting.FileSystemObject")
Set f = fs.GetFolder(chemin)
Set sf = f.Files
For Each wbo In sf  ' parcourir les fichiers du répertoire et tester le nom du classeur et l'extension
    If wbo.Name <> wbbase.Name And Right(wbo.Name, Len(ext)) = ext Then
        Workbooks.Open (chemin & "\" & wbo.Name)
        Sheets(1).Activate
        ActiveSheet.Columns("B:B").Insert Shift:=xlToRight, CopyOrigin:=xlFormatFromLeftOrAbove
        ActiveSheet.Range("B1").Value = "Date"
        Workbooks(wbo.Name).Close SaveChanges:=True
    End If
Next wbo
Set f = Nothing: Set fs = Nothing: Set sf = Nothing
Application.ScreenUpdating = True
End Sub