jpg转bmp的问题

我在网上找到一段能有效把jpg转到bmp的代码，但它读的是文件
我把jpg文件加入资源，请问应如何修改，使其处理jpg资源？
代码如下：

HBITMAP ImageLoad(LPCTSTR szFile, HBITMAP hRet)
{
LPPICTURE gpPicture;
HANDLE hFile = ::CreateFile(szFile, GENERIC_READ, 0, NULL, OPEN_EXISTING, 0, NULL);
if(INVALID_HANDLE_VALUE == hFile)
return false;
DWORD dwFileSize = ::GetFileSize(hFile, NULL);
ASSERT(-1 != dwFileSize);
LPVOID pvData = NULL;
HGLOBAL hGlobal = ::GlobalAlloc(GMEM_MOVEABLE, dwFileSize);
ASSERT(NULL != hGlobal);
pvData = ::GlobalLock(hGlobal);
ASSERT(NULL != pvData);
DWORD dwBytesRead = 0;
BOOL bRead = ::ReadFile(hFile, pvData, dwFileSize, &dwBytesRead, NULL);
ASSERT(FALSE != bRead);
::GlobalUnlock(hGlobal);
::CloseHandle(hFile);
LPSTREAM pstm = NULL;
HRESULT hr = ::CreateStreamOnHGlobal(hGlobal, TRUE, &pstm);
ASSERT(SUCCEEDED(hr) && pstm);
hr=::OleLoadPicture(pstm, dwFileSize, FALSE, IID_IPicture, (LPVOID *)&gpPicture);
ASSERT(SUCCEEDED(hr) && gpPicture);
pstm->Release();
OLE_HANDLE picHandle;
gpPicture->get_Handle(&picHandle);
HDC hdc = ::CreateCompatibleDC(NULL);
ASSERT(hdc);
::SelectObject(hdc, (HGDIOBJ) picHandle);
hRet = (HBITMAP)::GetCurrentObject(hdc, OBJ_BITMAP);
DeleteDC(hdc);
return hRet;
}