save an attachment of a message arrived via Bt

Hi,

I'm developing an application that sends an archive(txt, jpg or amr) via bluetooth and open it when the mobile recives de message.

Now I want to save the attachment of this message, the file, and then open it. But I can't save this attachment...
I'm using CBaseMtm class and Body() method but I can take the body.

How can I save the attachament?
Which method must be used?

Best Regards,
Elena.