use strict; 
use warnings;
my $label     = "some string";
my $apex      = 10; # some number
my $reference = "somefile.txt";
my $name      = "out.txt";

open IN, "<", $reference or die "Cannot open file $reference.\n";
open OUT, ">", "temp_marker_$name" or die "Cannot open file temp_marker_$name.\n";
while(<IN>) {
    my @fields = split; # cannot remember what awk splits on by default
    if( $fields[0] eq $label
	and $fields[2] <= $apex
	and $fields[3] >= $apex ) {
	    print OUT $_;
    }
}
close OUT;
close IN;