use strict;
use warnings;

my $header_lines = $ARGV[0] // 0;
my $footer_lines = $ARGV[1] // 0;

my $whole_input;
# slurp whole file into one scalar variable
{local $/ ; $whole_input = <DATA>};
# (this can exceed memory if data is too much)

# define what line is in regular expression language:
# not newline x (zero or more times) + one newline after
my $line_regex = qr/[^\n]*\n/;

# treat whole input as string and substitute lines with empty strings:
$whole_input =~ s/\A (?:$line_regex){$header_lines}   //x; 
                  # delete some lines from the beginning
$whole_input =~ s/   (?:$line_regex){$footer_lines} \z//x;
                  # delete some lines from the ending

print $whole_input; # now it is not whole, and you can parse

__DATA__
Header 1
Header 2
Text 1
Text 2
Text 3
Text 4
Text 5
Footer 1
Footer 2
Footer 3