domain, share, and smbclient
I usually make sure /etc/samba/smb.conf contains the same domain name as used by the vista computer, even if it is a workgroup and not a domain.
Set the share up so with the login name that will come from the Vista machine.
Map that user to an existing linux user or create a user of the same name as will be mapped from the Vista machine.
Finally, use smbclient to create the mapped user's name/password.