looks nice, this might inspire me to learn regex. I don't know if this would be possible (and it would probably be very difficult to make) but what would be really cool is if you could set 2 variables, a pre and post..and then the script/program would tell you the regex needed to get from pre to post. Just a thought if anyone wants to try that :p
Anyway nice job and I'm sure I'll be using this in the future :)