Help needed with Homegear Projection Screen

Hi all.
I have a Vera Edge with RFXTRX433 and it all works perfectly fine with my LightwaveRF devices.

… then I got creative. I bought an electric projection screen from Homegear, careful to make sure that it had a 433MHz remote, and plugged it in, and pressed the remote… nothing… ok, not quite nothing… I can see the bytes received in the RFXTRX settings window on Vera, and there are different bytes received for up/down/stop buttons from the projector remote… but no new device appears.

So how can I add a new device and then map these received bytes to those three remote commands (up/down/stop) ?

Am I in “you need to create a plugin” territory? and if I am, is there a good place to go to learn?

thanks