Non-unicode program support?

Hi, I'm new to mac. In Windows' international setting, I can select a language to use for non-unicode programs, so that non-unicode characters in the selected language (such as song tags) can be displayed properly. But in Leopard, I cannot find the equivalent setting. Some songs with non-unicode tags are not displayed properly in iTunes, although they are fine in iTunes on my Windows computers. Also, I have some non-unicode contact information in Palm Desktop synchronized from my Treo phone. It looks OK in Palm Desktop on Windows, but not on Leopard.
Does such setting exist in mac os x?
Thank you.