Как при помощи WinAPI создать прозрачные окна?

HWND WINAPI CreateWindow(
  LPCTSTR lpClassName,
  LPCTSTR lpWindowName,
  DWORD dwStyle,
  int x,
  int y,
  int nWidth,
  int nHeight,
  HWND hWndParent,
  HMENU hMenu,
  HINSTANCE hInstance,
  LPVOID lpParam
);

SetWindowLong (hWnd, GWL_EXSTYLE, GetWindowLong(hWnd, GWL_EXSTYLE) | WS_EX_LAYERED);
SetLayeredWindowAttributes (hWnd, 0, (255*70)/100, LWA_ALPHA);

BOOL (WINAPI *pSetLayer)(HWND,COLORREF,BYTE,DWORD);
int CTXPDlg::SetWndTransp(HWND hWnd, int transp)
{
    HINSTANCE hMod = LoadLibrary("user32.dll");
//WINSHELLAPI HINSTANCE APIENTRY ShellExecuteA(HWND hwnd, LPCSTR lpOperation, LPCSTR lpFile, LPCSTR lpParameters, LPCSTR lpDirectory, INT nShowCmd);
//WINSHELLAPI HINSTANCE APIENTRY ShellExecuteW(HWND hwnd, LPCWSTR lpOperation, LPCWSTR lpFile, LPCWSTR lpParameters, LPCWSTR lpDirectory, INT nShowCmd);
//    HWND hWnd = CDialog::m_hWnd;
 // ShellExecute(NULL,"open","notepad.exe",NULL,NULL,SW_SHOWNORMAL);
    if(hMod)
    {
        pSetLayer = (int(__stdcall*)(HWND,COLORREF,BYTE,DWORD))GetProcAddress(hMod,"SetLayeredWindowAttributes");
        if(pSetLayer)
        {
            if(SetWindowLong(hWnd,GWL_EXSTYLE,0x80000))
            {
                if(!pSetLayer(hWnd,0,255-transp*255/100,0x02))
                    MessageBox("Error pSetLayer","Error",MB_OK|MB_ICONSTOP);
            }
            else
                MessageBox("Error SetWindowLong","Error",MB_OK|MB_ICONSTOP);
        }
        else
            MessageBox("Error GetProcAddress","Error",MB_OK|MB_ICONSTOP);
    }
    else
        MessageBox("Error load user32.dll","Error",MB_OK|MB_ICONSTOP);
    if(!FreeLibrary(hMod))
        MessageBox("Error FreeLibrary","Error",MB_OK|MB_ICONSTOP);
    return transp;
}

#define _WIN32_WINNT 0x0500
#include <windows.h>
 
INT_PTR CALLBACK DialogProc(HWND hwndDlg, UINT uMsg,
    WPARAM wParam, LPARAM lParam);
 
int main(int argc, char *argv[])
{
    HMODULE hInstance = GetModuleHandle(0);
    DialogBox(hInstance, MAKEINTRESOURCE(100), 0, DialogProc);
}
 
INT_PTR CALLBACK DialogProc(HWND hwndDlg, UINT uMsg,
    WPARAM wParam, LPARAM lParam)
{
    static HBRUSH BgBrush;
    switch (uMsg)
    {
    case WM_INITDIALOG:
        BgBrush = (HBRUSH)GetStockObject(BLACK_BRUSH);
        SetWindowLong(hwndDlg, GWL_EXSTYLE,
            GetWindowLong(hwndDlg, GWL_EXSTYLE) | WS_EX_TRANSPARENT | WS_EX_LAYERED
            );
        SetLayeredWindowAttributes(hwndDlg, 0, 180, LWA_COLORKEY | LWA_ALPHA);
        return TRUE;
    case WM_CTLCOLORDLG:
        return (INT_PTR)BgBrush;
    case WM_CTLCOLORSTATIC:
        SetTextColor((HDC)wParam, 0x00FF00);
        SetBkColor((HDC)wParam, 0x808080);
        return (INT_PTR)BgBrush;
    }
    return FALSE;
}

#include <winresrc.h>
 
100 DIALOGEX 0, 0, 150, 8
EXSTYLE WS_EX_TOOLWINDOW | WS_EX_TOPMOST
STYLE WS_VISIBLE | WS_POPUP | DS_CENTER
FONT 30, "Tahoma", 800
{
    CTEXT "Превед!", 101, 0, 0, 150, 8
}