Mark,
Access does not natively support the output of a report to PDF format.
The only way this can be done is to "print" the report to a pdf writer.
If you don't already have one, there are a number of good ones
available, free or cheap. I use pdf995 myself. Then, in the design
view of the report, go to the File|Page Setup menu, and set the printer
for the report to your pdf driver. Then, you can use an OpenReport
macro to run the report, and it will be outputted to a pdf file.