Controlling AV amp sound from Youview?

[Condi]

Im trying to get the Youview remote to control the sound level from my Denon AVR-520BT amp. Its set up as follows

Youview box - Denon AVR- 520BT AV receiver - Samsung K series TV

Now, as the Youview box is at the start, and its all HDMI connection, can I not enable the AV receiver to take instructions from the Youview box? If so, how?

[scjgreen]

Would be a job for HDMI CEC if all of the components support it.