Like he said above, I don't think there is a way to tell it which screen to go to when you hit the home button, but I've figured out basically how to set which screen it will go to.
From what I've been able to tell messing with the screens, if you have anywhere from 2-4 screens, hitting the home button will take you to the screen all the way on the right. After that, if you have anywhere from 5-7 screens, the home button takes you to the fourth screen counting from the left, which means if you have 7 screens, it takes you the middle one.
So, basically, if you have 2 or 3 screens, setup the rightmost screen as your main home screen, and if you have 4-7 screens, set the fourth screen from the left as your main home screen.