Yes, such a script would be easily possible.
Maybe have a look at the damagetracker script, which keeps statistics on damage spread over locations:
[damagelog.pl][1]
Its basically just a bunch of regexp-triggers filling a hash with the collected data.
Should be just as easy to make a **/you fire.*bth: (\d+) Roll: (\d+)/** Regexp.
[1]...
2009-12-07 09:30:35 UTC in eXtensible PERl scripTable MUD client
