Maybe your Avant has the (sometimes optional) STB-C - Set Top Box Controller?
Then you could use a cable (IR) from the output on the back of the Avant to the "input" (recieving area/spot) on the Apple TV and hide the Apple TV behind the Avant!
Or you are looking for this:
This can be put on top of the Avant.
Ralf
My Beo: Beosound 3000, Beolab 4000, Beo 4 DVD, Beolab 5000/Beomaster 5000, Beovox S45.2 with Stands, Beosystem 7000 black with Beolink 7000, Beolink 1000, F1000 (3 cubes), Beovox 5000, Beovox 3000, Attyca 1.