Connecting a blackberry as a modem using BIS connection

Hi. I'm new and didn't know where to start this thread so I appologise if it is in the wrong place. I want to connect my blackberry 9700 via USB to my windows 7 enabled laptop and use it as a modem. I can do that no problem however it uses normal WAP/APN so I get charged for data transfer. What I was thinking is if it is possible to take my service book settings and apply them some how so I can use BIS and if this is possible maybe a step by step guid. I download old games off torrent sites(games no longer sold) and want download it however I can't find a torrent app and my favourite torrent converting website decided it nit gonna run anymore. So now I have to make an alternet plan. Any help would be usefull. Using Blackberry Bold 9700 on Cell See South Africa with once off monthly BIS service