VPN? does your company have a BES server? If it does then it will be a secure connection into the company network. You or the IT guy can check with Blackberry for info on setup for the BB. My thought is you do not have a BES server and they gave you either old info or have no clue that protocol was around for NT and windows 2000 and was designed for PC's.
This may help
MS-CHAP v2