Here is a function for converting any windows icon to an ARGB Image.
Enjoy. 
Thomas Arlt
Maker of the free google translate client "Transmiti"
http://www.transmiti.org
Image* Icon2Image(HICON hIcon)
{
BITMAP bm;
ICONINFO iconInfo;
GetIconInfo(hIcon, &iconInfo);
GetObject(iconInfo.hbmColor, sizeof(BITMAP),&bm);
int width = bm.bmWidth;
int height = bm.bmHeight;
int bytesPerScanLine = (width * 3 + 3) & 0xFFFFFFFC;
int size = bytesPerScanLine * height;
BITMAPINFO infoheader;
infoheader.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
infoheader.bmiHeader.biWidth = width;
infoheader.bmiHeader.biHeight = height;
infoheader.bmiHeader.biPlanes = 1;
infoheader.bmiHeader.biBitCount = 24;
infoheader.bmiHeader.biCompression = BI_RGB;
infoheader.bmiHeader.biSizeImage = size;
// allocate Memory for Icon RGB data plus Icon mask plus ARGB buffer for the resulting image
MemoryBlock* pMemBlock = new MemoryBlock((size*2+height*width*4)*sizeof(uint8));
uint8* pixelsIconRGB = (uint8*)pMemBlock->getData();
uint8* alphaPixels = (uint8*)(pixelsIconRGB+size);
uint32* imagePixels = (uint32*)(alphaPixels+size);
HDC hDC = CreateCompatibleDC(NULL);
// Get Icon RGB data
HBITMAP hBmpOld = (HBITMAP)SelectObject(hDC, (HGDIOBJ)iconInfo.hbmColor);
if(!GetDIBits(hDC, iconInfo.hbmColor, 0, height, (LPVOID) pixelsIconRGB, &infoheader, DIB_RGB_COLORS))
return NULL;
SelectObject(hDC, hBmpOld);
// now get the mask
if(!GetDIBits(hDC, iconInfo.hbmMask, 0,height,(LPVOID)alphaPixels, &infoheader, DIB_RGB_COLORS))
return NULL;
int x=0;
int currentSrcPos=0;
int currentDestPos=0;
int linePosSrc = 0;
int linePosDest = 0;
int lsSrc = width*3;
int vsDest = height-1;
for(int y=0; y<height; y++)
{
linePosSrc = (vsDest-y)*lsSrc;
linePosDest = y*width;
for(x=0; x<width; x++)
{
//pixels from Icon are stored in BGR vertical and horizontal flipped order
currentDestPos = linePosDest+x;
currentSrcPos = linePosSrc+x*3;
// BGR -> ARGB
imagePixels[currentDestPos]=(((uint32)((((pixelsIconRGB[currentSrcPos+2] << 0x10 /*Red*/) | (pixelsIconRGB[currentSrcPos+1] << 8 /*Green*/))
| pixelsIconRGB[currentSrcPos] /*Blue*/) | ((alphaPixels[currentSrcPos]?0:255) << 0x18))) & 0xffffffffL);
}
}
Image *pImage = new Image(Image::ARGB, width, height,true);
pImage->setPixelData (0, 0, width, height, (uint8*)imagePixels, width*4);
deleteAndNull(pMemBlock)
DeleteDC(hDC);
return pImage;
}