[exim] Using delay_warning_condition with a separate-file do…

A while ago [1] I got some good information here about using
queue_smtp_domains = /path/to/queue.list
where the separate file is a flat list of domains with some "*."
prefixes, as follows.
example.org
*.example.org

I now want to suppress delay warnings for messages to domains in the
same list. I think I want something like this:

  delay_warning_condition = {$if \
      ${lookup{$domain}wildlsearch{/path/to/queue.list}}{no}{yes}}

but I'm not using keys and values in the file, just presence or absence.

Am I on the right track?

Thanks,
Adam


[1] Thread starting with
http://www.exim.org/mail-archives/exim-users/Week-of-Mon-20051003/msg00155.html