Need a function to read any type of word file which may include different language using php

Well, I've a Php class which convert .doc, docx, xls and pdf file to text format. It's successfully converting if it's content is "English". But now I'm trying upload a word file with different language e. g. Japanese. But unfortunately it's not converting to text format. So I need you can fix my existing class or give me a new function or class that read any word document with different language. If you can do this job, let me know. I want to start it right away. Thank You.