John,
edit:// You cannot create / share (just any) folder sitting within NetApp volume.
What you can do though, is to create a qtree within a volume & share it out - I believe the end result may be what you are after.
Regards,
Radek
edit:// Apparently I was talking rubbish (Jon, thanks for pinging me): you can share a volume, a qtree and a folder, should you wish to do so. There are some further details in this doc: http://www.netapp.com/us/library/technical-reports/tr-3771.html
It may be worth trying creating a share from a Windows mmc console if other methods fail.