If you're totally new to programming you may not appreciate this but with DBI and DBD::CSV you get the ability to run SQL statements on comma separated files like that. It's great for large or interrelated CSV dumps
more simply you want open the file to move through the file line by line and split on a comma. see open perlfaq5 and while (and close). to get the fifth item something like this is a good way  $fifth_item = (split(/,/,$line))[4];