Need to pull a random static value from somewhere to a variable

I have an app that can point to 1 of 4 servers.  In an effort to pseudo load balance, everytime I launch the app, I would like a different server to appear in the server box.  I assume I could control this by doing a regwrite.

I could put the 4 server names into an array I suppose, or read them from a text file.  but how can I get autoit to choose one of them at random and store it to a variable?