Okay, here's my idea (I confirmed that you can do this with your receiver).
You can assign the digital inputs to different sources. Assuming that you are using a digital input for your CD player and that you aren't using HDMI for both the CD player and video source, the you can do this: assign the input jack used for the CD player to the input that you are using for video. Then, to select audio from the CD player instead of from the video source: with the video source selected on the receiver, you can hit the "AMP" button on the remote, and hit the "A/D" button to toggle through the audio inputs for that source. Assuming that you are using your remote currently to select the CD input, then you wouldn't need to push many more buttons than if you were to use the remote to select the CD input.
Alternatively, you could get a remote control that can learn and run macros (sets of multiple commands). With that, you could set it up to switch to the CD input and switch inputs on the TV with a single button press.