my $base = $row->{'  base addr. (hex)'};
$reqhash{$base} = $row;

##</code><code>##

use Data::Dumper;
print Dumper( $row );

##</code><code>##

my $base = "$row->{'  base addr. (hex)'} $row->{' end addr (hex)'}";
$reghash{$base} = $row;

##</code><code>##

my $base = $row->{'  base addr. (hex)'};
my $end = $row->{' end addr (hex)'}";
$reghash{$base}{$end} = $row;