Trying to get stop, FF, RW, and play to work with a device called Mohu Channels that uses a proprietary god-awful remote. Fortunately, a USB keyboard does work with the device. I've had some success mapping most of the functions to my Harmony One and flirc, and found out through trying all keyboard combos with the hard-wired keyboard that Fn+F4 does play, Fn+F5 is stop, Fn+F8 is RW, and Fn+F9 is FF.
So I'm trying to map these 4 keys to my Harmony One and flirc.