Two options.
1) Use the Perform section in the mIRC options.
2) Use a small script like
on *:start:{
.server irc.network1.com -j #chan1,#chan2,#chan3
.server -m irc.network2.com -j #chan1,#chan2,#chan3
.server -m irc.network3.com -j #chan1,#chan2,#chan3
}
Replace irc.networkN.com with the actual irc network addresses and #chanN with the correct channel names.
Personally I prefer, and recommend, the 2nd option.
Riamus & I are counter-posting again.
