i have tried using the perl "-C" switch to "tell" perl how to expect command line input, but it does not work.
How do you know? Maybe you have an old perl which doesn't support that option. Maybe you have a typo. Show your code.

this likely means that it is a cmd.exe problem and not perl. i think a similar solution is necessary to allow unicode input in windows too.
Yes, cmd.exe is responsible for display (all those ??). So try searching microsoft.public.win32.programmer.international or msdn ... also 'help cmd'