Sub Modifier_Presentation()
Dim chemin$, present$, PptApp As Object
chemin = ThisWorkbook.Path & "\" 'à adapter
present = "MaPresentation.pptx" 'à adapter
Set PptApp = CreateObject("Powerpoint.Application")
PptApp.Visible = True
With PptApp.Presentations.Open(chemin & present)
.Slides(4).Shapes("Label1").OLEFormat.Object.Caption = Feuil1.[E3]
End With
End Sub