I'm not sure I understand your question right. If you want to see just the grep commands at the end of your post you can use somehing like this

use strict;
use warnings;

my @filenames = qw{filename1 filename2 filename3};
my @datas =qw{DATA1 DATA2};

foreach my $filename (@filenames) {
    foreach my $data (@datas) {
        print "grep -c $data $filename \n";
    }
}
[download]

to convert the DATA1 / DATA2 to lowercase is left as an exercise for the reader :-)
cheers, si_lence