Thank you for answer, George!
Yesterday, I was able to import PD model (CDM) into Erwin using ERwin import options. There It is possible import either CDM file or PDM file but my point of view should be exist a option to export to other tools. XMI could be a standard to be followed in this case.
I will ask to SAP about this and maybe we shouting loud enough, they accept it.
tks.