Padding string to left

Question

How can one pad a string to left in objective c. E.g if I have an integer value of 6 I want it to be displayed as 06.

I use stringByPaddingToLength: but

Answer 1

for completness (using * placeholder):

NSString *paddedNumberString = [NSString stringWithFormat:@"%0*d", amountOfZeros, numberNSInteger]