Mixed character (English and Japanese) strings are not UTF-8 encoded correctly on Japanese OS by windows API - WideCharToMultiByte

Hi,

I have a Windows (MFC) application that passes a mixed character (English and Japanese) string like"Templete_DRAFT-4_final_コメント– Notepad"to a website using Request(CHttpConnection::HTTP_VERB_POST, remoteFileCopy, NULL, 1, NULL, _T("HTTP/1.1"), INTERNET_FLAG_DONT_CACHE | ((dwServiceType == AFX_INET_SERVICE_HTTPS) ? INTERNET_FLAG_SECURE : 0))).

Earlier the Japanese characters were displayed as ?(questions marks) but then I used windows API "WideCharToMultiByte(CP_UTF8,0,m_sDocName, -1, buf, sizeof(buf),NULL,NULL);" to encode it to UTF-8. And It works well with English OS but on Japanese OS the encoding is not accurate. The text is coming @ web site as"Templete_DRAFT-4_final_

コメンチE20-メモ帳"

would someone advise me to get a solution at the earliest.

Thanks