WndProc доступ к non-static объектам

class Element {
public:
    Element() { }
    HWND Hwnd;
    string Class;
    string Name;
    void(*Clicked)();
    int ID;
};
 
class Window {
 
public:
    Window(HINSTANCE);
 
    void MakeWindow(string, int, int);
 
    void CreateButton(string, string, int, int, int, int);
 
    void CreateTextBox(string, string, int, int, int, int);
 
    void ReadMessages();
 
    void CreateSignal(string, string, void(*f)());
 
private:
    static LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
    HWND hwnd;
    HINSTANCE hInst;
    int CurID;
    vector<Element> elements;
};

BOOL MyClass::Create()
{
    m_hWnd = CreateWindowEx(..........
                                        NULL,
                                        m_hInstance,
                                        this);
}
 
 
LRESULT CALLBACK MyClass::WndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
    LONG dwNewLong;
    MyClass* pWin;
 
    if(uMsg == WM_NCCREATE)
    {
        dwNewLong = (long)(((LPCREATESTRUCT)lParam)->lpCreateParams);
        SetWindowLong(hWnd, GWL_USERDATA, dwNewLong);
        return TRUE;
    }
    else
    {
        pWin = (MyClass *)GetWindowLong(hWnd, GWL_USERDATA);
    }
 
    if(pWin) return pWin->OnMessage(hWnd, uMsg, wParam, lParam);
 
    return 0;
}
 
LRESULT CALLBACK MyClass::OnMessage(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
    switch(uMsg)
    {
        case WM_CREATE:      OnCreate(hWnd, wParam, lParam);   break;
        case WM_PAINT:       OnPaint();                        break;
        case WM_DESTROY:     OnDestroy();                      break;
        default:             return DefWindowProc(hWnd, uMsg, wParam, lParam);
    }
    return 0;
}

LRESULT CALLBACK MyClass::WndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
    MyClass *pWin = (MyClass *)GetWindowLongPtr(hWnd, GWL_USERDATA);
 
    switch(uMsg)
    {
        case WM_CREATE:
        {
            pWin = new MyClass(hWnd);
            SetWindowLongPtr(hWnd, GWL_USERDATA, (LONG_PTR)pWin);
        }break;
 
        case WM_DESTROY: if(pWin) delete pWin;
        default:
            if(pWin) return pWin->OnMessage(hWnd, uMsg, wParam, lParam);
            else return DefWindowProc(hWnd, uMsg, wParam, lParam);
    }
 
    return 0;
}
 
LRESULT CALLBACK MyClass::OnMessage(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
    switch(uMsg)
    {
        case WM_CREATE:      OnCreate(hWnd, wParam, lParam);   break;
        case WM_PAINT:       OnPaint();                        break;
        case WM_DESTROY:     OnDestroy();                      break;
        default:             return DefWindowProc(hWnd, uMsg, wParam, lParam);
    }
    return 0;
}

LRESULT CALLBACK Window::WndProc(HWND ahwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
    switch (msg)
    {
    case WM_COMMAND:
        for (int i = 0; i < elements.size(); i++) {
            if (LOWORD(wParam) == elements[i].ID)
                elements[i].Clicked();
        }
        break;
    case WM_DESTROY:
        PostQuitMessage(0);
        break;
    default:
        return DefWindowProc(ahwnd, msg, wParam, lParam);
        break;
    }
 
    return 0;
}
 
LRESULT CALLBACK Window::WndProc2(HWND ahwnd, UINT msg, WPARAM wParam, LPARAM lParam) {
    LONG dwNewLong;
    Window* pWin;
 
    if (msg == WM_NCCREATE)
    {
        dwNewLong = (long)(((LPCREATESTRUCT)lParam)->lpCreateParams);
        SetWindowLong(ahwnd, GWL_USERDATA, dwNewLong);
        return TRUE;
    }
    else
    {
        pWin = (Window *)GetWindowLong(ahwnd, GWL_USERDATA);
    }
 
    if (pWin) return pWin->WndProc(ahwnd, msg, wParam, lParam);
 
    return 0;
}