how to use PX_Blob in activex for ppt add-in

void CBrowserResOcxCtrl::DoPropExchange(CPropExchange* pPX)
{
  ExchangeVersion(pPX, MAKELONG(_wVerMinor, _wVerMajor));
  COleControl::DoPropExchange(pPX);
  PX_Resource(pPX);
}
void CBrowserResOcxCtrl::PX_Resource(CPropExchange*  pPX)
{
	//////////////////////////////////////////////////////////////////////////
	if (pPX->GetVersion() == (DWORD)MAKELONG(_wVerMinor, _wVerMajor))
	{
		if(!pPX->IsLoading())
		{
			_variant_t vContent;
			m_CreateHtml.CreateVariantFromFile(&vContent,....);
			BYTE by[4];
			DWORD dw = vContent.parray->rgsabound->cElements;
			WORD h,l;
			h = HIWORD(dw);
			l = LOWORD(dw);
			by[0] = LOBYTE(l);
			by[1] = HIBYTE(l);
			by[2] = LOBYTE(h);
			by[3] = HIBYTE(h);			////////////////////////////////////////////////////////////////////////
			m_hRes = GlobalAlloc(GPTR, dw+4);
			if(m_hRes != NULL)
			{
				BYTE* pMem = (BYTE*)GlobalLock(m_hRes);
				if(pMem!=NULL)
				{
					///*(DWORD*)pMem = dw;
					pMem[0] = by[0];
					pMem[1] = by[1];
					pMem[2] = by[2];
					pMem[3] = by[3];
					BYTE* pTemp = NULL;
					SafeArrayAccessData(vContent.parray, (void **)&pTemp);
					for (int n=0;n<dwLen;n++)
					{
						BYTE by;
						by = pTemp[n];
						pMem[n+4]=pTemp[n];
					}					
					BOOL f = PX_Blob(pPX, _T("BlobRes"),m_hRes);
					SafeArrayUnaccessData(vContent.parray);
					GlobalUnlock(m_hRes);
					m_hRes = NULL;
				}
				else
				{
					HGLOBAL hTmp = NULL;
					BOOL b = PX_Blob(pPX, _T("BlobRes"), hTmp);
				}
				GlobalFree(m_hRes);
				m_hRes = NULL;
			}
			else
				BOOL b = PX_Blob(pPX, _T("BlobRes"), m_hRes);
		}
		else
		{
			BOOL b = PX_Blob(pPX,  _T("BlobRes"), m_hRes);
			if(m_hRes!=NULL)
			{
				BYTE* pMem = (BYTE*)GlobalLock(m_hRes);
				DWORD dwLen = GlobalSize(m_hRes);
				_variant_t vContent;				
				HRESULT hr;
				long lngOffset = 4;
				UCHAR chData;
				SAFEARRAY FAR *psa = NULL;
				SAFEARRAYBOUND rgsabound[1];
				rgsabound[0].lLbound = 0;
				rgsabound[0].cElements = dwLen-sizeof(DWORD);
				psa = SafeArrayCreate(VT_UI1,1,rgsabound);
				while(lngOffset < dwLen-4)
				{
					chData    = (UCHAR)(pMem[lngOffset]);
					hr = SafeArrayPutElement(psa, &lngOffset, &chData);
					if(FAILED(hr))
					{
						printf("错误");
					}
					lngOffset++;
				}
				vContent.vt = VT_ARRAY|VT_UI1;
				vContent.parray = psa;
		m_CreateHtml.CreateFileFromVariant(vContent,....);
				GlobalUnlock(m_hRes);
			}
			GlobalFree(m_hRes);
			m_hRes = NULL;

		}
	}


}