How to use ReadDirectoryChangesW() method with completion routine?

VOID CALLBACK FileIOCompletionRoutine(
  [in]                 DWORD dwErrorCode,
  [in]                 DWORD dwNumberOfBytesTransfered,
  [in]                 LPOVERLAPPED lpOverlapped
);

typedef struct MyOVERLAPPED {
    OVERLAPPED overlapped;
    MyData *data;
} MyOVERLAPPED;

MyOVERLAPPED *overlapped = malloc(sizeof(*overlapped));
memset(overlapped, 0, sizeof(*overlapped));
overlapped->data = // my data here
ReadDirectoryChangesW(/* ... */, &overlapped->overlapped, MyCallback);

static void CALLBACK MyCallback(DWORD errorCode, DWORD tferred, LPOVERLAPPED over)
{
    MyOVERLAPPED *overlapped = (MyOVERLAPPED *) over;
    MyData *data = overlapped->data;
    free(over);
    // etc.
}