If you use Data-Filter-Advanced Filter you can use the 12 ?s as your filter.

You need a column header - let's say it is Values, and let's say your data
is in column A

Then in C1 type Values and in C2 type ????????????

Then select a cell in column A and go to Advanced Filter. Set C1:C2 as the
criteria range, and clikc on OK


"jdanker" wrote:

I have a spreadsheet with only 1 column of data, but 18,000 lines. Is there
an easy way to find all cells that contain exactly 12 characters? I tried
searching for ???????????? and ************ but it finds every cell.