Despite the title of your post, you're not asking for a sharp code, right? You just want to get A/B/C back. As you've guessed, the reset may have wiped out the comcast upgrade. So you have a few options: exchange your remote for another one, post the model of your cable box and someone may be able to give you the codes for just the missing buttons, or buy/build a JP1 cable and load the upgrade back in yourself. Option one is free. Option three will cost $15-$30 and a few hours figuring out what to do and installing some software. Post over at the hifi-remote.com forums to find the cable and file you need, if you go with the third option. The benefit of the third option is that, once you have a cable and understand the software, you can make that remote do just about anything. I'm also assuming your remote has a 6-pin connector in the battery bay. If it doesn't, then option three and probably option two are off the table.