Numbering unique value -new column

Discussion created by droidgis on Jan 22, 2014
Latest reply on Jan 29, 2014 by jimcousins
first of all - my english is basic :) -sorry

I have a problem:
I want to paste contents from "column1" to "column2" with numbering, but i don't want "copy ID". I would numbering unique value anew.

For example:
Column1: Value in Column: A,B,B,B,C
I want to get: Column2: 1A,1B,2B,1C

Anyone know how to do it  in ARCGIS ?