Don't, you will just attract needless attention, just try to be cool, and don't sweat it, if admins ask just tell them a straight answer, not to mention you said that your friend gotten your account banned, and if admins were to ever found out about your old account then they could very well check the logs and find out that the time your account was banned it wasn't registered on your ip, but your friends ip, so there's no reason you should apologize for a friend's mistake, it's his fault, not yours, so keep your head high and good luck out there