// keep this handle handy as we need it for further RIL commands
HRIL rilHandle;

...

HRESULT hr = RIL_Initialize(
   1,                  // index of the RIL port to use (e.g., 1 for RIL1:)
   &resultCallBack,    // this is a pointer to your result call back method
   &notifyCallback,    // this is a pointer to your notify call back method
   RIL_NCLASS_ALL,     // all notification (except device specific)
   (DWORD) this,       // custom param (could be a pointer to an instance of a class)
   &rilHandle);        // returned handle to RIL instance


...

void CALLBACK resultCallback(
   DWORD dwCode,
   HRESULT hrCmdID,
   const void *lpData,
   DWORD cbData,
   DWORD dwParam)

{
   // handle the results

...

void CALLBACK notifyCallback(
   DWORD dwCode,
   const void *lpData,
   DWORD cbData,
   DWORD dwParam)
{
   // handle the notification