I'm suspecting that SMB or CIFs support on OS 9 is painful. There was some 3rd party package (see Macupdate.com) that allows you to access PC shares (Maybe PC Exchange?). Mounting it on your desktop should get NUDC to be able to save backups to that mount.

Might be easier to use an Airport Extreme with an HD hung off that. I'm not sure how OS 9 would play with that though. You're in a painted corner there.
_________________________
Geoff Miller
MadCow Studios
Toluca Lake, CA

...we're outstanding in the field....