void TransparentStretchBlt(HDC hDC, LONG left, LONG top,
                           LONG width, LONG height,
                           HBITMAP hBitmap,
                           LONG bmLeft, LONG bmTop,
                           LONG bmWidth, LONG bmHeight,
                           COLORREF colorMask)
  {
    HDC hMemDC, hStretchDC, hMaskDC;
    HBITMAP hStretchBm, hMaskBm,
            hOldMemBm, hOldStretchBm, hOldMaskBm;
    COLORREF oldColor;

    // Create the memory DC's.
    hMemDC = CreateCompatibleDC(hDC);
    hStretchDC = CreateCompatibleDC(hDC);
    hMaskDC = CreateCompatibleDC(hDC);

    // Create the bitmaps needed for the memory DC's.
    hStretchBm = CreateCompatibleBitmap(hDC, width, height);
    hMaskBm = CreateBitmap(width, height, 1, 1, NULL);

    // Select the bitmaps into the memory DC's.
    hOldMemBm = (HBITMAP)SelectObject(hMemDC, hBitmap);
    hOldStretchBm = (HBITMAP)SelectObject(hStretchDC, hStretchBm);
    hOldMaskBm = (HBITMAP)SelectObject(hMaskDC, hMaskBm);

    // StretchBlt to a colored DC.
    StretchBlt(hStretchDC, 0, 0, width, height,
               hMemDC, bmLeft, bmTop, bmWidth, bmHeight, SRCCOPY);

    // BitBlt to a monochrome DC.
    oldColor = SetBkColor(hStretchDC, colorMask);
    BitBlt(hMaskDC, 0, 0, width, height,
           hStretchDC, 0, 0, SRCCOPY);
    SetBkColor(hStretchDC, oldColor);

    // Transparent BitBlt technique.
    BitBlt(hDC, left, top, width, height,
           hMaskDC, 0, 0, SRCAND);
    BitBlt(hDC, left, top, width, height,
           hStretchDC, 0, 0, SRCPAINT);

    // Restore the memory DC's.
    SelectObject(hMemDC, hOldMemBm);
    SelectObject(hStretchDC, hOldStretchBm);
    SelectObject(hMaskDC, hOldMaskBm);

    // Delete the allocated bitmaps.
    DeleteObject(hStretchBm);
    DeleteObject(hMaskBm);

    // Delete the allocated memory DC's.
    DeleteDC(hMemDC);
    DeleteDC(hStretchDC);
    DeleteDC(hMaskDC);
  }