Infrared remote (e.g. Logitech Harmony) with Wetek OpenELEC

Wetek OpenELEC is a small box running OpenELEC. OpenELEC is a media center based on Kodi. In comparison to a Raspberry Pi running OpenELEC, Wetek OpenELEC includes a TV tuner (DVB-C/T, DVB-S oder ATSC). So you don’t have to find a compatible tuner by yourself and have everything integrated in a nice little box. Shipment includes an AirMouse. This is a remote which can be used as a mouse due to built-in motion sensors. Because I already use a Logitech Harmony as an universal remote I also wanted to control Wetek OpenELEC with this remote. Wetek OpenELEC is a special edition of Wetek Play (differences between these two). So getting an infrared remote to work with Wetek Play should be pretty similar.