IP Tunneling Setup

This is a basic project. I currently have a few very large Windows email servers which have our email marketing software on them. In order to send email we need IPs routed to this server. We want to purchase linux VPS's with a few IPs on each server and have them tunneled into our large Windows servers. Basically, what we need is a simple web based/hosted interface where we can simply enter the main IP of the VPS, the username, password, IPS, and the Windows server IP. I would simply want to enter all this information, click submit, and have all of the IPs on the VPS tunneled to the mailing server of our choice. I've attached a simple mock up made in Paintbrush showing what I am looking for. I need this done very quickly and I know its is quite the easy project. I just need something very user friendly that will not have an problems with stability.