Must be careful with characterset of ADODB.Stream

_StreamPtr spStreamIn ; //stream from the definition file
(spStreamIn.CreateInstance (__uuidof(Stream)));
(spStreamIn->Open (vtMissing, adModeUnknown, adOpenStreamUnspecified, "", ""));
spStreamIn->Charset = _T("UTF-8");// _T("Unicode");
hr = spStreamIn->LoadFromFile(_T("c:\\users.txt"));
spStreamIn->Position =0;
_bstr_t input_xml = spStreamIn->ReadText(adReadAll);