The Rex uses Perl Compatible Regular Expressions (PCRE).. at is at least very similar. You might get into issues where you have to escape things (such as a quote), but that you can generally figure out by starting with something simple, and building up with a little trial and error. The authoritative source for PCRE is http://perldoc.perl.org/perlre.html , and if you google PCRE tutorial, or Perl Regular Expressions Tutorial, you might find a few things that are a bit more "how do I get started." This one looks promising: http://www.troubleshooters.com/codecorn/littperl/perlreg.htm
... View more