Once you have a template created, you can go into the Setup Wizard, and select your new device template in the A/V devices section.
You then specify how the audio and video connections to the reciever are connected, this sets up the appropriate pipes. If you do not connect this to a tuner, then it is assumed that LMCE will handle switching your A/V device's inputs, and it will create a new media scenario button (LiveTV DirectTV), which when you press, will change the TV and reciever inputs, etc. Orbiter will also change to the LiveTV remote, so that you can control the cable box.
But to recap:
* Connect your directTV reciever to your TV and/or reciever, directly.
* Make sure you have templates for your A/V gear the reciever is connected to
* Add those devices in the A/V wizard. If any A/V devices depend on others, add those last.