smbclient and passwords

[naughton at domino.danielwoodhead.com]

I am trying to backup some files to an NT workstation from a samba server.
The samba server provides domain logon, file, print serving for the NT
workgroup.    Is there anyway to include something like

smbclient \\machine_name\backup_share -N -c "put backupfile.tar.gz"

and use the username/password from smbpassword to authenticate the request?
I would like to set it up as a cron job without having the password in the
script. ( I need a workaround until the backup tape drive comes in.) The NT
station is a member of the Samba Domain - but that doesn't seem to make any
difference.

Thanks
Dan