If the ProE part is solid, take a STEP output and import it into Catia. If it has surfaces, IGES output would give a better result. If you do this type of translation, you get only a dumb solid in Catia. This means that you cannot edit the model in Catia as there would not be any features. For more information on translators I would suggest you visit the website www.cadcam-e.com.