This is a perfect job for Tie::File, along with an array slice. Note that the @file array holds the file open, so if you change the array in any way, you'll also modify the file live-time. If you aren't editing the file, best to take a copy of the tied array, then untie @file before doing any processing.

use warnings;
use strict;

use Tie::File;

my $file = 'a.txt';

my $num_headers = $ARGV[0];
my $num_footers = ++$ARGV[1];

tie my @file, 'Tie::File', $file or die $!;

my $stop = scalar @file - $num_footers;

my @section = @file[$num_headers..$stop];

untie @file;

print "$_\n" for @section;
[download]

Input file:

h1
h2
data
more data
even more data
blah
f1
f2
f3
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Result:

$ ./header.pl 2 3

data
more data
even more data
blah
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-stevieb