Sandboxie Support

Hey guys! I'm trying to play Diablo 3 with my wife on my computer. I have SoftXpand Duo Pro and I've had luck running a number of games just fine. However I can't get around Blizzard games. Most people say that if you add '-launch' at the end of the shortcut address it should load the game, but I keep getting an error stating that Battle.net is already open on another user.

My question is, how do I get around this? Am I just typing Launch wrong or can SandBoxie help me solve the problem?

Thanks guys.