Replace numbers to letters

How to replace numbers to letters?
eg: 1=a.
2=b
3=c
4=d

Eg: -1=e
-2=f
-3=g
-4=h

hey,

You can use (int)Convert.ToChar("a") to convert a char to his ascii code, and then - 96 to get a = 1. (a in ascii = 97).