jabxyz,
One person comes to mind, Travis Laird. This guy is a BES guru. He will be able to tell you if it can be done or not. He is busy sometimes but hit him up. He will respond. If he doesn't know, then I am sure he can point you in the right direction. Try contacting him via email and Facebook. See the link below for the info.
Travis Laird | BlackBerry Internet Service IP Ranges