What VPN client do you use on the PC to connect to your VPN server at work? If it's the Cisco VPN client, you need the Macintosh version and you need to copy the profile settings that you have on the PC to the Mac. You'll find a version on the following site (I got this link from an Ubuntu forum).
http://realvpn.real.com/#download
Next time, please don't forget to include the client software you're using as well. All you said was that you were dialing to the VPN. You were not specific about the VPN client used on either the PC or the Mac, nor were you specific about the type of VPN server that was being accessed (Cisco, OpenVPN, etc.)
The issue here seems to be the VPN client you're using and the VPN server being accessed, which is why Apple can't help you. They're only there to help you with problems that reside on your Macintosh, not on how to connect to something using the Macintosh. That question would be better sent to the company that's makes the VPN software.