use Win32::API;

my $DataToEncode = "Test1 Test2 Test3";

my $return_sring = undef;

use Win32::API;
  $function = Win32::API->new(
      'IDAutomationDMATRIX6', 'FontEncode',['P','N','N','N','P']
  );

   my $string =  $function->Call('FontEncode');

##</code><code>##

  $function = Win32::API->new(
      'IDAutomationDMATRIX6', 'FontEncode',['P','N','N','N','P'], 'P'
  );

##</code><code>##

  $function = Win32::API->new(
      'IDAutomationDMATRIX6', 'FontEncode',['P','N','N','N','P'], 'P', '_cdecl'
  );

##</code><code>##

  $function = Win32::API->new(
      'IDAutomationDMATRIX6', 'FontEncode',['P','N','N','N','P'], 'P', '__stdcall'
  );

##</code><code>##

my $string =  $function->Call($str1, $n1, $n2, $n3, $str2);

##</code><code>##

my $string = '' x 500; # Big enough ?
$string =  $function->Call($str1, $n1, $n2, $n3, $str2);