Mastercam is not a parametric software so you will not get the model tree inheirant to creo2. You can export files in almost any generic file format available (iges, parasolid, step, etc.)
The creo2 translator is an add-on. you must purchase this translator to open native files.
You can save your files out of creo2 in other formats, I know IGES, I believe step and parasolid as well. If you need to get an output file instead I would always opt for the parasolid first, the step second and the iges only as a last resort.
IMO step will give you the best results from creo2 to Mastercam. When importing assemblies of native creo2 and parasolids they can loose their assembly positioning. Step assemblies from creo2 always come in in the correct position.