When adding non standard text, foreign letters or characters to documents you may need to add them using short cut keys. ALT+ (numbers) see the links below to see what short cuts are needed.
For some programs such as WLP2 printing software, it will not accept all short cuts. The workaround is to create the word in a Text editing program such as MS word, take a snapshot and then add it as graphic to the label. It doesn't look as crisp but it works.
http://www.oreillynet.com/pub/a/xml/excerpts/unicode-explained/tables-writing-characters.html