Sub CATMain()
dim mybody
dim hbrid1,hbrid2
dim monset1,monset2
set mybody=catia.activedocument.part.Mainbody
set hbrid1=catia.activedocument.part.hybridbodies
set hbrid2=mybody.hybridbodies
set monset1 = hbrid1.add
set monset2=hbrid2.add

monset1.name="apres"
monset2.name="dessous"
End Sub