I have a Zip Code list that has a new record for each zip code. So for example, if a city has 3 zip codes, it will list in 3 entries. I want to combine all in one entry.

For example:

County-City-Zip Code
Orange-Buena Park-90620
Orange-Buena Park-90621
Orange-Buena Park-90622
Orange-Buena Park-90623


So i would like to program a separate entry that will list all 4 zip codes (in the above example). The thing is that there are numerous cities for each county, and i don't want to manually concatenate each one. I would rather have an if formula that will automatically concatenate the same city's zip code together since there is so much data on this spreadsheet.

I am pretty good with excel formulas but this one is stumping me right now... it's Monday.