Apparently there is a “30 second skip” command that is available to the Motorola DCT6412 III PVR. If you have this version of the Comcast brand (and other cable carriers, to be fair) you can use the following instructions to map the 30 second skip feature to a button.
1. Make sure the PVR is on. Press and release the “Cable” button.
2. Press and hold the “Setup” button. Release after the “Cable” button blinks twice.
3. Using the number pad, type “994? and look for the “Cable” button to blink twice.
4. Press and release the “Setup” button.
5. Using the number pad, type “00173?.
6. Press the button that you wish to have the FFW feature mapped to. the person that posted this recommend a button that isn’t used normally. he used the “HD Zoom” button in the lower right corner.