Command line switches allow you to change the behaviour of mIRC when it is first run. The switches can be used by creating a Windows Shortcut to the mIRC executable and appending the switches to the target filename, eg.:
"C:\Program Files\mIRC\mirc.exe" -sUndernet
mIRC supports the following command line switches:
Makes mIRC connect to the specified server and port on startup.
Makes mIRC join the specified channels on connect.
Specifies the password required to join the channel.
Sets your main and alternate nicknames.
Makes mIRC use the specified file in place of mirc.ini.
Sets the data path where mIRC saves mirc.ini as well as other files and data. If -r is specified without a path, the path is set to that of the mIRC executable.
Makes mIRC avoid use of the registry. This includes not adding irc:// and ircs:// link support.
Prevents mIRC from connecting to a server on startup if that option is enabled in the mIRC options dialog.
This is a combination of the -r and -noreg switches.