If you have an I-call capable radio, just enter what the manual specifies as the general I-call "group" code. Then scan as usual. As you encounter unit ID's that you prefer not to listen to, just lock them out as their ID is displayed. This will help you narrow down the ID list until you only hear the ID's that you're interested in.
From what I've been hearing, the last 4 ID numbers tend to correspond with the officer's unit numbers. There are a few exceptions, especially with 2 and 3 digit unit numbers, but the 4 digit unit numbers are generally the same.
