TCHAR buff[MAX_PATH]=L"\0";
VARIANT var;
VariantInit(&var);
var.vt = VT_BSTR;
var.bstrVal = SysAllocString(buff);
ITextDocument *ITD;
IUnknown *pUnk = NULL;
SendMessage(hwnd,EM_GETOLEINTERFACE,0,LPARAM(&pUnk));
pUnk->QueryInterface(IID_ITextDocument,reinterpret_cast<LPVOID*>(&ITD));
HRESULT hr=ITD->Open(&var ,tomWordDocument,0);