Unable to get the vlookup property of the workshee

Sub VLookup()
    
    Dim sRes As String
    Dim F1, F2 As Worksheet
    Dim LastLig1 As Long
    Dim plage As Range
    Dim C As Range
    Dim i As Integer
    Dim rs As String
    Dim Resultat As Range
    
    Set F1 = Worksheets("fichier existant")
    Set F2 = Worksheets("fichier importé")
    Set plage = Sheets(2).Range("G1", Sheets(2).Range("G65536").End(xlUp))
    'LastLig1 = F2.Cells(Rows.Count, "A").End(xlUp).Row
    'For ligne = 2 To LastLig1
    i = 1
    For Each C In plage
    i = i + 1
    rs = F2.Range("G" + CStr(i)).Value
   <bold>  F2.Range("Z" + CStr(i)).Value = (Application.WorksheetFunction.VLookup("rs", F1.Range("G:G"), 2, False))</bold>
      Debug.Print rs
    If IsError(F2.Range("Z" + CStr(i)).Value) Then
        F2.Range("Z" + CStr(i)).Value = old
    Else
    F2.Range("Z" + CStr(i)).Value = Nouveau
    End If
    Next C
    
    
    'Debug.Print rs
    
    
End Sub