Help with RaceNet Leagues

After complaining for nearly a year, private league play with AI is now available through RaceNet. I have set up a league with one friend but I can't find a way to add him to the league. I have to invite him to each race and his finishing position and points don't show up in the race results.  I have gone to friends and selected him; he is added to my account but I can't figure out how to invite him to the league. Help.