use strict;
use warnings;
use Inline C => Config =>
MYEXTLIB  => 'd:\path\to\CrappyLibrary.dll',
INC => '-Id:\path\to',
BUILD_NOISY => 1;

use Inline C => 'DATA';

my $result = RegisterClient2($client_id, $S{read_IP});

__DATA__
__C__
#include "Easy4ApiDef.h"

##</code><code>##

use strict;
use warnings;
use Inline C => Config =>
MYEXTLIB  => 'd:\path\to\CrappyLibrary.dll',
INC => '-Id:\path\to',
BUILD_NOISY => 1;

use Inline C => 'DATA';

my $client_id = 5; #numeric
my $read_IP = 'whatever'; #string
my $result = wrap_RegisterClient2($client_id, $S{read_IP});

__DATA__
__C__
#include "Easy4ApiDef.h"

int wrap_RegisterClient2(int cl_id, char* read_ip) {
  return RegisterClient2(cl_id, read_ip);
}