Cocoa/Objective C: Convert numbers to strings using Japanese unicode characters

Converting numbers to strings is no problem, but the string created uses ascii numbers. I am inserting the number in a Japanese sentence. The character itself is correct, say 3, for example, but the width and positioning should be a little different when typing in Japanese. As a result the number looks cramped up against the following character. Is there any clever non-manual way to convert 1 to １, 2 to ２开发者_开发问答, 3 to ３, etc.?

For lack of any better ideas, I wrote up a not-so-elegant category solution that manually converts each character. If anyone has a better solution, please let me know.

#import "NSNumber+LocalizedNumber.h"

@interface NSNumber()
-(NSString*)convertRepresentation:(unichar)character;
@end

@implementation NSNumber (LocalizedNumber)

-(NSString *)localizedNumber {
    NSString *languageCode = [[NSLocale preferredLanguages] objectAtIndex:0];
    if([languageCode isEqualToString:@"ja"]) {
        NSString *numberString = [self stringValue];
        NSUInteger length = [numberString length];
        NSMutableString *convertedString = [[NSMutableString alloc] initWithCapacity:length];
        for(NSUInteger index = 0; index < length; index++) {
            unichar character = [numberString characterAtIndex:index];
            [convertedString appendString:[self convertRepresentation:character]];
        }
        return [convertedString autorelease];
    }
    return [self stringValue];
}

-(NSString*)convertRepresentation:(unichar)character {
    switch (character) {
        case '1':
            return @"１";
        case '2':
            return @"２";
        case '3':
            return @"３";
        case '4':
            return @"４";
        case '5':
            return @"５";
        case '6':
            return @"６";
        case '7':
            return @"７";
        case '8':
            return @"８";
        case '9':
            return @"９";
        case '0':
            return @"０";
        default:
            return nil;
    }
}