[Samba] Auth without domain by machine instead of user ?

[Vitaliy Romanyuk]

Is subj possible?

How to authorise connection immediately by connected machinename and
skip user auth (map "mach" into some "john") without domain creation?

Ubuntu 10.4, XP SP3, in a "classic" config (with user-auth) Samba
works flawless.

I'm new in Samba and have tried only next
1. useradd -d /false -s /bin/false MACH$
then I've looked in a shadow and found that a passwd field contains
":!:" so
2. usermod -p "" MACH$
and then unlocked this account too
3. smbpasswd -a -n -m MACH
4. allowed nullpasswords in smb.conf

Then (after service restart etc. of course) any login attempts
regardless via gui or net use \ipc$ command fails (or maps onto
"nobody" when a guestaccess enabled)

Do Samba without domain accepts and uses machinenames at all?