VPN over DSL

I have been sharing a DSL over my home network using a Lynsys router. It setup quick and easy and has worked like a champ. I would now like to hook into the office via our company VPN, but can’t get out of my home network. A friend has suggested setting up a box with two nics. One for the local network and the second for direct link to the DSL Modem. Split the DSL line so one goes to the router and the other goes to the second nic of the VPN box. Sound logical, but will it work? Would I need to setup two hardware profiles with alternately disabled nics or will they play together in peaceful coexistence?