Sub ModifierPresentationExistante()
Dim PptApp As PowerPoint.Application
Dim PptDoc As PowerPoint.Presentation
Dim sld As PowerPoint.Slide
Dim shp As PowerPoint.Shape
Set PptApp = CreateObject("Powerpoint.Application")
PptApp.Visible = True
Set PptDoc = PptApp.Presentations.Open("C:\Desktop\test\teste.pptm")
With PptDoc
'Effectue un collage dans la 2eme diapositive
Set shp = .Slides(2).Shapes.AddTextbox(msoTextOrientationHorizontal, 70, 320, 600, 50)
shp.TextFrame.TextRange.Text = Range("C3")
'(...)
End With
End Sub