The only "channel" the DVD recorder is going to find is the channel 3/4 modulated output from the DirecTiVo. You'll get sigificantly better recording quality by using the a/v outputs instead.
But hopefully you're not sooo overly egg-nogged to think that every satellite channel is available at once.

And hopefully you aren't trying to use it to record shows on a timer/schedule...
You'll use the DVD recorder just like a VCR hooked to the TiVo - refer to the DirecTiVo instructions on hooking up a VCR to the unit (I think it's shown in the manual...) . It will always be set to record from the A/V inputs, and you'll control the channel/show playback from the DirecTiVo.
Jeff