Use this link, and then click the search button, and then search the user created teams, then when you find one, click add to game.
My team from the one we did last year is still on there, so if you still have a team on there from last year, and didn't delete it, it should still be there.
I simulated a game with my old team, against the Magic Rat Pacers from last year, and everything worked fine.
The site looks a little different than it did last year, but it still appears to work the same, and it still has the option to generate play-by-play for the boxscore.
It does appear that if we make exhibition teams to simulate with, we will have to use the $42 million salary cap, the only way to get around that is to have a paid league.
If you already have an account on there, use this link below, then click the Manage My Team(s) button at the top, and it will take you to the League Overview, and you can click on the link to the Draft Center.
If you don't have an account on there, just sign up real quick, it's free, then you can go to the above link to create your exhibition team, then use the link I put at the very top of this post to simulate against other user created teams.