use strict;
use warnings;

my ($handle, %hash, $a, $c);
my $myfile = 'whatever.dat';

open $handle, $myfile;
<$handle>;
while ($_ = <$handle>) {
    $a = substr($_, 6, 1);
    $c = substr(<$handle>, 10, 1);
    <$handle> for (0..4);
    $hash{$c} = $a;
}