I have a diagram at a link that'll last for 7 days showing what I'm trying to do.
I currently have one network card in each computer. I can install another if it'll help. There's one internet (cable, static IP) connection at each location.
If I'm at a machine on the right side, I should be able to access the server over the intranet. All right-site WAN traffic should be unencrypted traffic going out over the internet. There should be no pressing need to directly access a PC at left-site.
If I'm at a machine on the left side, I should be able to access the server over a secured VPN connection via the internet. All other traffic (web browsing, e-mail retrieval, etc.) should go out unencrypted over the internet.
I'm aware of the potential security issues with split tunneling, but I need to do it. The server essentially is a closed unix/linux system I have no access to and know nothing about. The people who have installed it dropped off the face of the earth, but it runs. It is not a FTP/WEB/etc server. It just has a custom application running on it. Folks log in and run the app.
I'm aware there's a contingent out there that'll recommend getting a linux box of some sort combined with some sort of proxy. I haven't done that before and money/time are a consideration. I promise to look into that as a longer term solution if that's the recommendation, but I need to get this up and running.
My fallback option at the moment is to leave the system totally open and drop VPN, which is a pretty horrible option.
I know there are routers that will do what I want, but I've been searching the internet and nothing mentions it by name. I can't go about buying all the VPN routers on the market and testing them to see if they'll do what I need. I also thought if I got two cable internet connections at left-site, I could put two network cards in the PC's there and use one connection for VPN and a non-VPN wireless router for communication with the wild.
Any assistance is appreciated.