How can I map and list zip codes passed through on a route?

Hey all,

Very new to open maps. What kind of code would create a list of all the zip codes passed through by or within a certain distance of a navigation route? I managed to find code to map cities that are passed through on a route, but I can’t get it to do the same for postcodes.

I think it would be very useful to be able to input two coordinates on separate ends of a navigation route into some code, run it, and get a csv document of all the zip codes within say 10 miles of that route. Then maybe figure a way to run that through a javascript program that plugs those zip codes into another site like Craigslist, allowing you to view listings that are exclusively within close distance of a particular navigation route.

Much thanks