There is a link on my library page that explains how to enhance the mapping feature in Crystal reports to include maps by zip code or county. Unfortunately, adding these features isn’t free. You have to purchase additional map ‘layers’ for the MapInfo module in CR. MapInfo is now part of Pitney Bowes.
One of my readers, Robert Meyer, just let me know that he called Pitney Bowes and found that my pricing information was out of date. They used to sell zip codes and county maps one state at a time. A zip code map for a single state was $395 for one user. Now you can get a zip code map for all 50 states for $2,250 (still one user). Not that this is cheap but it is much better than before. A county map used to be $125 per state per user and it is now $495 for all 50 states.