for my $line (@lines_from_data_file) {
    my($idx,$fname,$sname,$loc,$time) = $line =~
        /^(\d+),("[^"]+"),("[^"]+"),("[^"]+"),(.*)$/;
}

##</code><code>##

perl -i.bak -ne "s/([\d\x22]),/$1.'|'/eg;print" datafile

# for some reason I can't use single quotes for a
# perl -e on Win32 so I have to use \x22 for "

##</code><code>##

@data = split /([\d"]+),/;