[otrs] Graphical stats report with non-Eurpean characters

Hi there, Does anybody have used any graphical stat report (bar chart, pie chart, ...) with Unicode text like Persian (Farsi), Hebrew or Japaness? I've tried it many times with Persian (Farsi) bu instead of Persian characters like "سلام", I see european characters with accent above just like "çãã". How can I correct this? Regards, Afshar Mohebbi