As Hippo suggested you can use Text::CSV to parse the file into an Array of Arrays which is a two dimensional array. For sorting then use the examples at this Perlmonks node to sort. The example that derby showed looks like what you need.

Edit: Here are a few more links about sorting on multiple columns. How would I sort a two-dimensional array by multiple columns?, http://www.perlhowto.com/sort_ordering_by_multiple_columns, http://www.nntp.perl.org/group/perl.beginners/2001/05/msg1442.html ,https://stackoverflow.com/questions/8556331/sort-across-multiple-columns-perl

What they all boil down to is using short circuiting in the sort to sort the next column if the current comparison returns '0'. Something like sort { $a->[0] cmp $b->[0] || $a->[1] <=> $b->[1] } @unsorted