Click
Account on top of this page, log in with the forum account you used to post in his thread, then look at your 3 Character Account slots.
If your old character is not amidst those 3 slots, but you remember the old "legacy" account name you used back then to play with it, click on
Bind legacy account and enter your old user/password.
If you don't remember your old "legacy" account name, you'll have to click
NasChat on top of this page and hope that Nabutso or Nasomi can help you recover it (I don't even know if it can be done).
Otherwise you'll have to create a new Character Account in one of those 3 slots. Level 30 isn't that bad to catch up, and there's a ton of new players to meet in the Dunes.
