I've just started learning Linux and all of the relatively basic commands over the past month, but I am having some trouble using the Grep command. I'm currently stuck on how to use the Grep command to search only one column of a CSV file for a numeric string that starts with two specified numbers. I'm specifically trying to list the lines that have a zip code that starts with "48", which zip code in this case is included in the 7th column of the CSV file. There is also other numeric data on each line, which is why I need to use the Grep command only on the "Provider" column. Any help to point me in the right direction will be appreciated, as I have been trying to figure this out for some time now and I think I may be slightly over-thinking what I need to do.
Here's an example of the CSV data I'm using:
Provider Hospital Total Discharges Average Covered Charges
49444 MI - Muskegon 53 18694.9
49007 MI - Kalamazoo 40 20494.25
48075 MI - Royal Oak 14 20386.28
48124 MI - Dearborn 34 34338.47