If you are using a Windows computer the answer is rather simple: Behold the Microsoft Keyboard Layout Creator - Free.
If the doesn't work you could use Microsoft hot scripts to code a program that will run in the sys tray yourself. I think you could probably find a port for Linux too.
Hot scripts is easy and you can copy and paste scripts until you are comfortable to write your own. They are very easy to write and you can learn about them here - http://ahkscript.org/ .