[wrxtasy]

Simplest way to do it is to program the FLIRC as a Full Keyboard, then cross reference the Kodi Wiki Keyboard control map.
Make sure when any Harmony remote is programmed, every button on the remote is assigned to a unique IR command with the Harmony Software.

Why ?

Well every one of those unique IR Harmony commands gets remapped to the Kodi Keyboard controls with the FLIRC software anyway.