It only recorded the top 100 back then. When you finish in the top 100 (or top 50 these days) that's called portalling because your ID is recorded in the round portal. No other IDs are kept (apart from ones for top ranks in eff and h/f).
The only other way to find your ID would be if your original account still existed, which it probably doesn't considering round 12 was like 10 years ago. Sorry.