Originally Posted By: Mpot
I wanted to create an alias so I could type /kb nick in the window and it would kickban them off the channel. But, I'm not sure how. How does mIRC know to take the nick, /whois it, +b the hostmask, and kick it? I tried $nick, but meh. Help?

The inbuilt 'ban' command is your friend. As Horstl mentioned, read the help. But to summarise:

The 'ban' command uses an inbuilt feature of mIRC called the IAL (Internal Address List). In other words, the hostname and username are in mIRC's memory pool.