use Inline::C;
$transbar = "\0"x66; 
$bardata = "3070202120200000000127203643012";
$rc =0;
$track = substr($bardata,0,20) . "\0";
$route = substr($bardata,20,11) . "\0";
$rc = barcode($track,$route,$transbar);
print "$transbar \n";
__C__
#include <windows.h>

// setup our data structures
typedef int (__cdecl *USPS4CB)(char *,char *,char *); 
HINSTANCE hDLL;
USPS4CB lpfnUSPS4CB;

//load the DLL
hDLL = LoadLibrary("USPS4CB");
if (hDLL != NULL)
{
   //get a pointer to the function we'll call
   lpfnUSPS4CB = (USPS4CB)GetProcAddress(hDLL,                                           "USPS4CB");

   if (!lpfnUSPS4CB) // problem loading the function
   {
      FreeLibrary(hDLL);       
// here we would kill our perl process or something, cause
// loading the library failed
// I don't do too much of this, so I'm not quite sure
// how to properly fail fatally
   }
}

// function for perl to call
int barcode(char *track, char *route, char *transbar) {
      // call the function
      return lpfnUSPS4CB(track, route, transbar);
}