Your AV receiver should be plugged directly into your TV, that's the whole point. You use one HDMI cable in between your AVR and the TV.
You plug your HR21 into the receiver using HDMI. You plug your DVD player into the receiver using HDMI.
Then you select which you want to use (HR21 or DVD player) by selecting the right input on the receiver with the receiver remote control. Whichever input you select on the receiver will show up on the TV. -- ♬ Music is life ♬
And then get ready for a substantial change in sound quality! It sounds like you are running pure analog stereo right now. Get those devices connected to the receiver via HDMI so you can get some real surround sound!