Here's a home brewed example of how to get your format. Similar to some others you have and probably will again receive.

#!/usr/bin/perl -w


my %segment = ();
$file = "source_data.txt";

# Open the source file ...
open (FILE,$file)||die "Can't open the source data file $file\n$!\n";

while(<FILE>){
    if (/,/){
        chomp;
        s/\"//g;  # no more double quotes
        my ($segname, @rec) = (split(/,/))[2,0,1];
        push @{$segment{$segname}}, \@rec;
        
    }
}

close (FILE);


foreach (keys %segment) {
          print "$_\n";  
          # let's get the new comma + space in there and print
          foreach (@{$segment{$_}}) {
                print join(", ",@$_) . "\n";   
            }
            print "end\n";
}
[download]