I'm not sure what you are attempting to do here since it would be far easier
just to work with (print from) the PDF, however, assuming that the PDF does
contain spot color information and you have a full version of Acrobat
(Acrobat Professional and not Acrobat Reader) you can save the pages in the
PDF off as EPS files that can be placed in Publisher.
If you plan on editing the information from the PDF it gets significantly
more involved, and I would recommend staying away from doing any editing to
any PDF, your best to go back and get the original native file that created
the PDF.