I have a setup working for my Somfy shutters (with the same remote control) that's like described here:
RPi talks to an Arduino through USB
Arduino talks to CC1101 through a 5V to 3.3V level translator
CC1101 sends the commands to the shutter.
There is code available on the itnernet for the Arduino & CC1101 & Somfy RTS part, and I modified the code to be able to send instructions per USB (up/down/my with the number of the shutter in argument because I have 12 shutters in my house). On the RPi, I have a program that activates the shutters at a programmable moment (through a text based file) and that also hears for connections on a TCP socket, so that I can connect to it with an Android app (also written by myself).
If you want to go that way, I'm ready to send you some source code and instructions.