Empty Channels in the lineup

[Carlo 4330]

What you do is add an additional lineup but don't assign it to any tuners.
None of your channels will get remapped this way but will stay using your normal guide.
You can then manually pick a different guide you've loaded and map a specific channel.

So if another near by guide has any of your missing channels, use it for just the missing channels.

Doesn't hurt to also check DirecTV and Dish as well for just the missing channels.
I prefer to google these channels and pull up a PDF you can quickly search.