Mapping Zip Code Data

I work in a Health Care (Hospital) data environment. I am attempting to map some of our data to zip codes within specified counties we serve. Some zip codes are served (Exist) in two counties. Can you display data within the zip for the county of interest without displaying the adjacent county portion of the same zip code?

My application is for displaying Queen Anne's County Maryland. Zip code 21620 will display in Kent County Maryland, even though a portion of it is actually in the geography of Queen Anne's. Can I display the QA portion without seeing the geography in Kent?

I can't seem to get this to work. I have tried to set the county as a territory. I can exclude 21620 and create a "Hole" in QA, or I can display 21620 and see Kent geography. But can't get 21620 to display only in QA county! Any help or suggestions? Thanks

The only thing I can think of is to refine the geocoding to street level with address. It will be accurate, but it will take you awhile to tell it what to look for for each individual request. Neither MapPoint nor MapInfo are great at geocoding at the street level without having refined search criteria input.
Evan

The way this was done for the Carnahan Group in Florida was to draw shapes
representing the actual coverage area, send behind roads, and use different
shading for shared areas.

See Mattys Consulting - Map Galleries (http://www.mattysconsulting.com/GalleryFrameset.htm), 3rd picture down