To add to auto-join, there is a dialog called 'Perform', in the 'Options' in the 'Connect' submenu in your mIRC options. You can type alias commands into that editbox, like /join #help. mIRC will perform those commands on connect to whatever server you choose. If you click on the Add button, a list of servers will come up, and you can add the commands you type in, for either one server, or all servers. mIRC will save whatever commands you choose, seperately, for each server.
I use the perform dialog to identify with NickServ on connect. It works nicely.
As for your mIRC favorites, you could write a seperate dialog if you wanted to, but there is one in your toolbar, and it contains an 'organize' button for editing preferences... I dont currently know of a command that would prompt that dialog, like if you wanted to put it in a channel popup, because it is just as quick to move the mouse up to the toolbar, accomplishing the same thing.
