How to convert a unichar value to an NSString in Objective-C?

I've got an international character stored in a unichar variable. This character does not come from a file or url. The variable itself only stores an unsigned short(0xce91) which is in UTF-8 format and translates to the greek capital letter 'A'. I'm trying to put that character into an NSString variable but i fail miserably.

I've tried 2 different ways both of which unsuccessful:

unichar greekAlpha = 0xce91; //could have written greekAlpha = 'Α' instead.

NSString *theString = [NSString stringWithFormat:@"Greek Alpha: %C", greekAlpha];

No good. I get some weird chinese characters. As a sidenote this works perfectly with english characters.

Then I also tried this:

NSString *byteString = [[NSString alloc] initWithBytes:&greekAlpha
                                                length:sizeof(unichar)
                                              encoding:NSUTF8StringEncoding];

But this doesn't work either. I'm obviously doing something terribly wrong, but I don't know what. Can someone help me please ? Thanks!