I'm using mIRC and in script editor section -> remote i added:
on *:start:{
server irc.TEST1.net -i YOUR_NICK -j #Channel1
server -m irc.TEST2.org +7000 -i YOUR_NICK -j #Channel1,#Channel2,password1,password2
}
Whit this after lunch mIRC everything is connected to diffrent networks and diffrent channels
