The answer is: yes. cablabel S3 supports Unicode (UTF-8). With UTF-8 you can enter and print characters of your language but also characters of other languages and special characters.
Characters not on your keyboard you can copy from Microsoft character map. By the way: you can add different language keyboards in Windows. (For more information go to Microsoft support.)
Before printing your label please check if UTF-8 is set for your printer. These setting you find in following menue:
Settings ➪ Interface ➪ Character set