It would require computer brain surgery so you could bypass their (perfectly good) built-in controller.
They do have a manual mode that *I think* you can use to operate it with a timer...but I'd suggest verifying even that before buying. (But that's not what you asked for anyway.)
No, they don't support it. The only third party control for the R420R line is from Bluefish, which makes it wireless and gives a few more options than the built-in controller.