look up help on the DOS "ROUTE" command, you can likely invoke a rerouting to the second gateway, before the 2nd mirc starts (im assuming your hitting the same network, so are going to need a temp reroute rather than a permanent one)
hint.
start/run/CND/ok/ and then ROUTE /?
PS: I havent done this myself, but i know this is how its done, I have had multiple ips and used routing to link certian ip ranges to each one.
