I have a worksheet with multiple columns, anywhere from 2 to 10 or more. These columns are lists of numbers (UPC codes, actually). The columns are of different lengths. Some numbers are common to all columns and some are common to only a few and some are unique to one column. What I need to do is combine the columns into a single list of numbers with no duplications. This will be a grocery store chain authorization list. I do this manually now. I would appreciate any help.