Editing VPN settings based on contents of text file

Hi all. Bit of a tricky one.

It looks like it’s fairly easy to create and connect to a VPN using either Apple or Shell script, but I can’t find anything about editing the settings of an existing VPN.

Basically, I’ve set up remote access to my desktop running 10.9 Server, However my ISP won’t do static IP without a business plan. I could get a dynamic DNS service, but I’m trying to cut out the middle man.

I’m using curl to get my public IP address and write it to a text file on dropbox (so all my devices can see it).
The next step would just be to update the VPN Host Name/Server Address based on what’s in that file, but I don’t really have any idea where to start other than an abundance of scripts for creating a new VPN from scratch.

It looks like it can be GUI scripted, but I’d prefer if it wasn’t, just to keep it behind the scenes.

It would appear that the setting for the client machines is stored in /Library/Preferences/System Configuration/preferences.plist under CommRemoteAddress