I don't believe the fog lights are controlled by the ECU, but I could be wrong as I haven't dug into the wiring diagrams.
If you want to run it via a toggle switch on your dash I would think it would be fairly easy. You just need a switch, access to 12V power, a relay, some wire, and likely a couple 1A diodes to prevent current backflow. The clean way is to run everything independent, use some wire taps to tie into the fog light wiring at the lights, and then use the diodes to isolate the two methods of turning the lights on. Alternately you could use the switch to power the existing fog light relay. Either way here's an example of how to wire one of those Air-On-Board push button switches so that your driving lights are tied to your high beam switch (which is the exact opposite of what you're trying to do, but it should give you a good starting point if your knowledge of electronics is limited).