This script is no longer maintained.
please use trigger.pl, it has all the features of replace.pl and much more.
I’ve written a script to convert your old replaces file to a triggers file: convert-replace-trigger.pl
This is not an irssi script. You should use this from the command line.
perl convert-replace-trigger.pl [irssi-dir]
if no directory is specified, it will asume you use the default ~/.irssi
You can still download the old script.