mkdir /tmp/winshare
mount -t smbfs //user@servername/sharename /tmp/winshare
... (share is now available as /tmp/winshare)
...
... (and when you're done, disconnect like this:)
umount /tmp/winshare
I only briefly tested this but it worked fine on a G4 powerbook, OS X 10.4.5 connecting to a Win2k fileserver. Hope that helps!!