Digital and analog trunking are programmed very much the same on a Pro-106. I believe that the issue you're having is that the Cobb County system is a trunked system (
Cobb County P25 Trunking System, Metro Atlanta, Georgia - Scanner Frequencies I believe) while the Cherokee County is Conventional Analog. Check out how to program a trunked system in your user manual or this easier to use one (
Easier to Read Pro-106/197/PSR500/600 Digital Scanner Manual).
Most basically for programming trunking systems, you first program in the frequencies (at least the ones indicated as control channels) and then program the Hex or Decimal (whichever your scanner uses - Hex is often for Uniden and Decimal for RS/GRE scanners) code associated with the talkgroup (how trunking systems indicate which channel) you want. For example, you first enter in the frequencies for the Cobb County system (either all or just those in Blue or Red), which tells the scanner how to receive the system. You then enter the talkgroup numbers (30509 for their first dispatch channel and 30509 for their second one). How you enter the frequencies and talkgroups are fully explained in the manual (yours or the easier one I linked to) and won't be detailed here.
In reality though, since programming trunked systems isn't nearly as easy as setting a frequency and you're done, I'd recommend you get the Radio Shack or GRE equivalent programming cable and the software for your scanner which is discussed here (also a good start on how to program the GRE series digital scanners like the RS 106)
Object Oriented Scanner Software - The RadioReference Wiki. It will save you loads of grief. Since most of the software has a 30 day free trial, try them all out and pick the one that you feel works best for how you work. Some folks get it better how one does it, others how another does it. They're all pretty good quality software.
Hope this helps point you in the right direction and good luck!
