use strict;
use XML::Simple;
use Data::Dumper;
use Tie::IxHash;

my     $Request_data = {};

tie my %NewOrder_data , 'Tie::IxHash';
tie my %r, 'Tie::IxHash';

my $request_xml = \%r;

 %NewOrder_data =  (        
                    'IndustryType'        => ['EC'], 
                    'CurrencyCode'        => ['840'],
                    'CurrencyExponent1'    => ['1'],
                    'CurrencyExponent2'    => ['2'],
                    );



my @keys = keys %NewOrder_data;
print "\n@keys\n";

    my $xmlDS = {
        Request => [
                {                
                NewOrder => [
                                \%NewOrder_data,
                            ],
                    }
            ],
        };

$request_xml = eval {
    my $xs = new XML::Simple(keeproot => 1, SuppressEmpty => 1, NoSort => 1);
    $xs->XMLout($xmlDS);
    };

print STDERR "\n\nxml :- >\n" . Dumper($request_xml);

__END__
Outputs:

IndustryType CurrencyCode CurrencyExponent1 CurrencyExponent2


xml :- >
$VAR1 = '<Request>
  <NewOrder>
    <IndustryType>EC</IndustryType>
    <CurrencyCode>840</CurrencyCode>
    <CurrencyExponent1>1</CurrencyExponent1>
    <CurrencyExponent2>2</CurrencyExponent2>
  </NewOrder>
</Request>
';