! ^

Use ! to repeat the last command typed at the keyboard.

Use ^ to replace a string from the last command with a new string. The syntax is the same as in unix: "^old-string^replacement"

Examples:

tell rasmusse Hi there, how are you? No-one by that name here.

^rasmusse^rasmussen You tell Rasmussen, 'Hi there, how are you?'

^you^you doing^ You tell Rasmussen, 'Hi there, how are you doing?'