Set CATIA = GetObject("", "CATIA.Application")

Set Document = CATIA.ActiveDocument
Set ProdDoc1 = Document.Product
Set docs1 = CATIA.Documents
Set products1 = ProdDoc1.Products

Set product2 = products1.Item(1)

Set Liste1 = Document.Selection
Liste1.Clear
Liste1.Add (product2)

Set Clashes1 = ProdDoc1.GetTechnologicalObject("Clashes")

Set Clash1 = Clashes1.AddFromSel
Clash1.ComputationType = 2
Clash1.InterferenceType = 1
Clash1.Clearance = 20

Clash1.Compute