my $Tree = new XML::Twig (
   TwigHandlers => {
     Filter =>
       sub {
         my ( $filterTwig, $filter ) = @_;
         my $filterName = $filter -> att( 'Name' );
         $filter -> set_att( Name => "$uniqueFilter" );
      }
  }
);
$Tree->safe_parsefile("c:/check.xml");
warn $@ if $@;

##</code><code>##

<?xml version="1.0" encoding="UTF-8"?>
<Settings Version="1.0">
   <Name>Capture</Name>
   <Buffer Size="16777216"/>
   <Filters Mode="Accept">
      <Filter Name="IP"/>
   </Filters>
</Settings>