I've been trying to work out how to ask this question so trying to solve it, well I haven't got a hope LOL, but here goes.

Assuming that sheet1 (which has 1 number per cell) and sheet2 are used here using identicle cells on each sheet, where sheet2 duplicates sheet1 except that sheet2 changes as per my query below.

How do you check a range of single number cells to see if a number only appears once then change that number to a zero?

For example:-

Sheet1 shows as (with headers for ease)

ABCDE
23123

Sheet2 would look like this:-

ABCDE
23023

So Col C, row (where ever it is on sheet1) changes from a 1 to a zero because it only appears once in the range of cells you ask it to look at. The range however will be a block of single cell numbers of multiple cols and rows of my choice as different sheets will be added in time plus the range will change at some also.

Hope I explained it well enough

Many thanks.