There are two control codes, SO (shift-out) and SI (shift-in) that can be used for this---SO to switch to another character set, and SI to switch back. So you

There are two control codes, SO (shift-out) and SI (shift-in) that can be used for this---SO to switch to another character set, and SI to switch back. So you SO to Emojicode, and SI back to Unicode.