If int* doesn't work, I would use the following. It's basically the same as what you ended up doing using Inline::C, but in Pure Perl. 

use Win32::API qw( );

my $register_client2 = Win32::API->new(
   $S{DLL_path}, 'RegisterClient2', 'PP', 'I',
);

sub register_client2 {
   my $ip = $_[1];
   my $id = pack('l', 0);  # Allocate space
   my $rv = $register_client2->Call($id, $ip);
   $_[0] = unpack('l', $id);
   return $rv;
}

register_client2(my $id, $ip)
   or die;

[download]

If the return value is just a boolean, you could do something more perlish. 

sub register_client2 {
   my ($ip) = @_;
   my $id = pack('l', 0);  # Allocate space
   $register_client2->Call($id, $ip)
      or return ();
   return unpack('l', $id);
}

my ($id) = register_client2($ip)
   or die;

[download]

Note: psz would indicate char** rather than char*. That's confusing.

In reply to Re: Calling a function form an external DLL with Inline::C on windows by ikegami
in thread Calling a function form an external DLL with Inline::C on windows by Anonymous Monk

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