Last Instance of a record in a list

[Mike952]

Hi Folks,

I want the word "Yes" to appear in column C, adjacent to the last record in a list of duplicate entries in a column.

(see attached).

e.g. the record 1405800475 (in Column A) should have "Yes" in cell C86.

Each week I add about 1000 new rows to the bottom of the list, so I need to be able to drag it down to keep the last record updated.

Hope this is clear.

Any help would as always, be gratefully appreciated.

Mike