I have two .dta files. The first contains three variables:

city - city name
county - the corresponding county name
zips - every zip code corresponding to the given city in a string format (for example: "92508 92503 92501 92505 92504 92507 92506 92502 92513 92514 92516 92517 92521 92522")

The second file simply contains one variable: zip_code (for example: "92505")

My aim is to create a variable in the second .dta file for county using the first .dta file. I can't think of a way to do so. Any advice?

**Note: I cannot use dataex for this post because the "data exceeds max linesize".