Without further details/examples, I assume that the reply always
- will start with your nickname
- is followed by (number:number)
- is followed by a number to represent asteroids
- is followed by a number to represent land
- is followed by some further number

The following remote script will calculate and reply back if all of the above conditions are met.
Code:
on *:text:*:#: {
  if ($regex($1-5,/^\Q $+ $me \E\(\d:\d\) (\d+) (\d+) \d/)) {
    var %roidhits = $ceil($calc($regml(1) / 10))
    var %landhits = $ceil($calc($regml(2) / $iif(($regml(2) > 200),10,20)))
    msg $chan %roidhits hits to Roid Kill; %landhits hits to Land kill
  }
}

The problem is how to prevent as much "false positives" in the text matching as possible. This may be improved only if you can provide more details, like
- do you chat on a single network only, or (if not) is the game running only on a specific networks (which network)?
- may the text occur in every channels, or in a specific set of known channels?
- is the person/bot sending the text always op in the channel?
- if "empire name" at the start is not always your own nickname: is it at least always a nickname of the channel?
- is "sector name" always made of single-digit numbers?
- is "91,300" a single, comma-formatted number (and won't contain a comma if below 1,000) or is it two numbers that are separated by a comma (and will always contain a comma)?
- is [DFA] always at the end of the reply? If not, is [something in square brackets without space] always at the end of the reply?

And finally, is the calculation correct at all? If not, please provide a couple of examples together with the intended x / y values smile