[exim] SQL-macros in auth-section

Hi!

I'm having some trouble getting a mysql-query to work from the auth-section.
This is what I have managed to peice together by googling and reading this
list :)

# route
route_domain2_com:
driver = manualroute
domains = domain2.com
route_list = * my.mailserver.tld
host_find_failed = defer
transport = remote_smtp_auth

# transport
remote_smtp_auth:
driver = smtp
hosts_require_auth = my.mailserver.tld

# auth
login:
  driver = plaintext
  public_name = LOGIN
  server_prompts = "Username:: : Password::"
  client_send = ${lookup mysql {SELECT username FROM mailsettings.mailauth \
       WHERE domain = '${domain:$1}'}}

I'm trying to get exim to use a specifict username/password for each domain
that my server is relaying mail to.
I have been fiddling with this for most of the day but cant get it to work.
I'm getting errors like this no matther how I write the lookup-code:

2005-06-16 18:11:03 1DiwxH-0004kS-5B <= from-user@??? H=localhost
(ll) [127.0.0.1] U=1000 P=smtp S=199
2005-06-16 18:11:03 1DiwxH-0004kS-5B == to-user@???
R=route_domain2_com T=remote_smtp_auth defer (0): expansion of "${lookup
mysql {SELECT username FROM mailsettings.mailauth WHERE domain = '${domain"
failed in login authenticator: "${domain" is not a known operator (or a } is
missing in a variable reference)

Can someone please explain what I'm doing wrong?

Btw.. I'm using exim-4.50

TIA

/Kalle