As an alternative (which I prefer due to the filename mangling that windows sharing sometimes does) I'd use NFS if the NAS supports it, so you'd then do:
mount -t nfs 192.168.xx.xx:/nas-drive /mnt/hda/share/nas
Note how I've mounted it within you're existing /mnt/hda/share folder? That lets you access it without creating new shares, etc in samba, etc and should be visible over your network/existing scripts to simplify things.
Of course, this won't work through reboots, so add:
192.168.xx.xx:/nas-drive <tab> /mnt/hda/share/nas <tab> nfs <tab> rsize=8192,wsize=8192,bg,noatime,tcp <tab> 0 <tab> 0
To your /etc/fstab (just add it to the bottom).
Couple of notes:
192.168.xx.xx is the IP of your NAS device
/nas-drive is the network path your NAS device shares
Where you see <tab> in the /etc/fstab hit the tab key instead of spaces.