As a general rule, bench warrants do not expire, and the warrant remains active until the individual gets arrested. Because you had already been to court, then the statute of limitations on the charge will likely not apply, especially if your absence was the reason the case went forward.
With that being said, find and talk to a local attorney that does business in that court. It's possible, even likely, that the State won't be able to go forward with the case because it is 15 years old, in which case the attorney can get your case dismissed. In the unlikely event they do want to try the case, an attorney may be able to get the warrant lifted. Make sure it is a local attorney who knows the players and how the local system works. If you try to handle it yourself, there's a good chance they'll execute the bench warrant and you'll go to jail.
The advice above is spot on and you should contact a local criminal defense attorney up in Dahlonega to help you sort it out. It will cost you a bit of money, but you will sleep better each night. The nightmare situation is when you get pulled over for a minor issue and they discover the bench warrant so the officer has little choice but to arrest you and transport you back to the local jurisdiction. Depending on where you are, that process can take a terribly long time and you may be held in a "no-bond" status until it is sorted out. Take care of this soon as you do not want that kind of interruption in your life.