Which version of FM? If it's earlier than FM8, then the marker text only supports FrameRoman encoding when using the English OS. Otherwise at FM8 and later, the marker text should be displaying in UTF-8.
AFAIK, you can't change the encoding used for the marker. IIRC, it's tied into the O/S code page, i.e. you need to be using the Chinese O/S version. Otherwise, you should upgrade to a newer version of FM that fully supports unicode.