I got these instructions off another forum. I tried it and it works.
1. Press the "cable" button at the top of the remote to put it into Cable Box control mode.
2. Press and hold the "Setup" button until the "Cable" button blinks twice.
3. Type in the code 994. The "Cable" button will blink twice.
4. Press (do not hold) the "Setup" button.
5. Type in the code 00173 for the 30 second skip.
6. Press whatever button on the remote you want to map the skip function to. (I used the lock button).