I would like to write a script to place in the startup Perform section to do
the following:

Join a newtork and authorise myself, then join a channel.
Then join a second network (without disconnecting from the first) and
identify myself, then join a channel on this network.

Any help appreciated.

maybe this will work..

on *:start: {
/server -m <adress>
/server -m <adress>
}

on *:connect: {
if (<network ect. undernet.org> isin $server) {
; Add you commands
/join <chan>
}
if (<network ect. undernet.org> isin $server) {
; Add you commands
/join <chan>
}
}

why not just script a auto join and auto identify script? they aren't that hard