Adding columns to the Users table?

RT 3.0.9, MySQL

Can anyone give me any suggestions about how to add additional columns of data to the ‘Users’ table? I can certainly do this via SQL and make accompanying changes to the html interface, but I suspect there is a better method. I’d rather not lump them all into the Exra Info or Comments sections if possible, as they’ll be tougher to use later. I need to add additional items (like Supervisor, Department, Employee ID number, etc.) that can be used later in custom scrips (I’m planning a scrip called Escalate, which will change ownership of a ticket to a person’s supervisor when the status is changed from “Open” to “Escalate” for example).