replace:

$row->[15] = '';
if ($row->[5] =~ /#[^ ]+/) {
   ($row->[15]) = $row->[5] =~ /(#[^ ]+)/;
}
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with (untested):

($row->[15]) = $row->[5] =~ /(#[^ ]+/ ? $row->[5] : '';

more readable, logically? same line as above, but split across a few lines:

($row->[15]) = $row->[5] =~ /(#[^ ]+/ 
    ? $row->[5] 
    : '';
[download]

ternary (aka. conditional) operator.