A family of Microsoft relational database management systems designed for ease of use.
You can, but...
Using attachments is not recommended. It is better to merely store the file path & name and use code to open/edit/manipulate it as required.
Regardless, to answer you question, see::
To export the report to a pdf file, you'd do something like (or you could also create a macro to do the same):
DoCmd.OutputTo acOutputReport,"YourReportName",acFormatPDF,"FullPathAndFileName4ThePDF"
To save the newly created PDF as an attachment, see:
http://stackoverflow.com/questions/4787149/how-to-auto-attach-images-in-access-2010-using-vba-macros