[Exim] wildcard blacklisting by HELO?

Hi there,

    I wish to black list at smtp time based on the HELO command. At
the moment I have a number of ACLs such as the one that follows,
hardwired into my exim.conf file.

  deny  message   = "Blacklisted HELO"
        condition = ${if
eq{$sender_helo_name}{youkickedmydog.net}{yes}{no}}

What I wish to do is actually be able to place all the restricted HELO
hosts into an external file and include wild cards.

i.e the file would have one host per line and would include entries such
as:

youkickedmydog.net
*.dialup.comcast.net

Thanks in advance.

Scott