Original Account to battle.net account ?

Hello everyone, I have a question about changing from an original log in account to the battle.net account system. My friend had opened an account with WoW and started a character with a particular name. That account went inactive for a while and then my friend wanted to try the game once more. We went through the motions of creating a battle.net account, and decided to take the 10-day free trial before they decided to subscribe to the game. The original character that was created was not in their character list, but the realm was still correct, even from a few months ago. So, the question is, is there a way to retrieve that character or is there a process through Blizzard to retrieve the character? My friend really liked that character and would like to continue using it. Thanks in advance for your time!