I am searching for William Barnett born abt 1775 and resided in Virginia. Boutetout or Greenbrier county

I am searching for William Barnett born abt 1775 and resided in Virginia. Boutetout or Greenbrier county. Our ultimate goal is to identify his parents. Therefor, we want to search 1800 census for a Barnett household with a male of 25 years old