Recently I posted a question in SO, but so far I got no answers. I wonder if I'm asking the wrong question.

This is the problem:

We need to design an application which offers a public http web service, but at the same time it must consume some services through a VPN connection from other existing company. There is no other alternative but to use a VPN connection to access those services. We want to host our application in some cloud infrastructure like Heroku or Amazon EC2. But there is no direct way to access the VPN services of the other company from there.

The solution I'm thinking, but I don't like is to have a different server to expose the services from that VPN. But this will require the setup of another server which I prefer to avoid. In the case this is the solution, can I use an Amazon EC2 instance to connect to a VPN? This is what I was thinking, is it correct?

I don't have experience using VPNs, tunnels or those kind of networking stuff. I will really appreciate if you can propose me an alternative solution, or just give me a comment.