On my host, I am using a VPN connection (OpenVPN) so all my host apps will have my VPN's IP address. If I use VirtualBox with Bridged Adapter, applications on my guest machine will have my Real IP address. I will essentially have 2 ip addresses.

Now, is there a way for me to somehow route specific apps on my host to use my guest's internet connection so I can have certain apps have my real ip address?
Ex: Firefox has my VPN Ip address and Thunderbird has my real ip address (picks up from guest's internet connection)

I am using WinXP on both Host and Guest and its not Linux but I thought maybe someone would know since I found similar threads.