Option Explicit
Sub modif()
Dim VBComp As VBComponent
Dim Ancien As String, Nouveau As String, Cible As String
Dim I As Long
With ActiveWorkbook.VBProject.VBComponents("thisworkbook").CodeModule
' pour le remplacement d'une ligne entière
For I = 1 To .CountOfLines
Cible = .Lines(I, 1)
If InStr(1, Cible, "IBD496") > 1 Then
Nouveau = Replace(.Lines(I, 1), "IBD496", "IU1232")
.ReplaceLine I, Nouveau
End If
Next
End With
End Sub