Repost - I screwed up something on the Imgur visibility settings. Sorry!
I wanted to share this for other servers (or single world players) interested in doing a portal system. The program used by the ComptuerCraft computer is called "Dialer". It consists of five files; four lua scripts and a startup file.
The code is mainly written by me, but I had help from code written by KJ4IPS and I had to copy ComputerCraft's code for "paintutils", to allow passing a monitor perhiperal to its drawing commands (which I thought would be easier than redirecting the terminal).
If desired, I can explain how any of the code works. The code itself should be self-explainatory. You may find it on GitHub: https://github.com/Gamealition/Dialer (there is a readme provided, for installation help). I used ComputerCraft, Mystcraft, OpenPeripherals and IronChests.
Please know that I have observed books go missing at random, using this system. I am not sure if it has been fixed since 1.1.1 but I would love to figure out why this happens, or how to reproduce it reliably.
I have a feeling the book is dropped from the slot and onto the ground, in unknown circumstances. If you have any advice, please share! In the interim, I just replace the books in creative mode.
Lua programming with ComputerCraft is great fun; this was my first time using CC but I have prior programming experience with Lua, amongst other things. I found Thomas Lauer's LUA cheat sheet to be of great help: http://thomaslauer.com/download/luarefv51.pdf
Incidentally, Direwolf20 himself had a portal system but I did not know of this. It seems to rely on more components (e.g. turtles and pipes) and is more than a year old, but may work better for you as an alternative. See https://www.youtube.com/watch?v=z6RmM7KP150 for the code review.