Update You can indeed execute scripts written in Unicode I was incorrect --> I was able to replicate your error on a Windows box if I saved the script in Unicode using Notepad. However, I got the same script to work fine if I saved it as UTF-8. (using Perl v. 5.8).
previous: I don't believe you can encode the script in UTF. You can use Perl to read various UTF Encodings to both decode(read) and encode(when writing) in various UTF formats, but your source still needs to be in ASCII if I read your post correctly.