Here is what you do:
1. You join a team. To get whatever title you want join them when they are at the rating to achieve that title.
2. After being on the team, you would default to 1000 Personal Rating. At this point, what you want to do is get a name change.
3. After you get your name change you will have The teams rating as personal rating and have 0-0. Record. I discovered this because I joined a 5v5 and got a name change. I currently have the Teams Personal Rating. It used to be 0 Personal before name change. And now it matches the team Rating. I am sure Blizz would notice no games played so play some games to make it seem real.
You can also use this to get weapons that require a high personal rating such as 2350. As well as gear!
Enjoy!
Zest