We'd need to know what your 7 classifications are. Assuming, for
instance, that the seven classes are based on the first 3 characters in
the zip code and assuming the zip code is in a cell by itself, you
could use a MID() or LEFT() function to derive just those first 3
characters, and then sort.

If you could post a Before and After view of how the data is presented
now and how you want it to look that would be ideal.