question about my son's visa

Has anyone had experience to bring kid by friends? My wife and I are in U.S.A right now for two years, and my son is in China. My wife and my son applied their visas in 2001, and both of them got visas, but due to some special reason, my wife didn’t bring my son over here. My friend will go to USA for his study this September. We want my son to apply for his visa again. If the visa officer asks who will bring my son over here, is it OK to say by a friend? Also is it possible for my son’s aunt to be with him during his application because my son is only 6 years old? Thank you for your advice..