How to determine if a word has an extended character?

I have a file which contains just one word. My task is just to find out if the word has any extended character. Thats all. I can use regex, but am not able to find out a regex pattern for extended character. Any hints? For example, if the file content is: sample, then the Perl code prints false; and if the file content is samplé, then the Perl code prints