You can often find the digital channel numbers for your local stations in a guide like http://www.titantv.com/
. Alternately, check if the local stations websites offer a link to their schedule. This will usually list the channel/channel digital identity. Another source for the digital channel numbers are the antenna choice/position/direction guides. Look at http://www.antennaweb.org
. Tvfool.com gives the direction and signal strength for all channel transmitters in your general area. Antennaweb.org is much more conservative and will only give the strongest stations in your area. That conservative list assumes an external antenna and clear path between the transmitter and your antenna.
In my area, the analog channel 7 became digital channel 7-1 . However, the channels 12 and 16 now transmit at 43-1 and 46-1 . However, after letting the TV do the auto-search, they are 12-1 and 16-1 when I type in the channel numbers on my remote.
I hope this helps. I might be able to provide a list of your local digital channels if you add a comment with your general location.