match data in two columns, enter info in certain cell

[mslavick]

Hi, I'm new here and fairly new to Excel. I'm not sure if this is a formula or VBA problem that I need help with. In column N, I have a list of 600,000 or so unique ID numbers. In column O, I have a list of 1,000 ID numbers. I want Excel to take a number from column O, find its match in column N, and in the row where it appears in column N, write "Yes" in column P. For example, in O1 is "123456." That number is matched at N1205. In P1205, Excel should write "Yes." Any suggestions? Thanks!

Matt

[Special-K]

in P1

=IF(ISNA(MATCH(O1,N$1:N$600000,0)),"","Yes")

and copy down as far as P600000 (P600,000)

[mslavick]

Hi, thanks for the reply! Unfortunately, it seems to be returning the Yes's in the first 1,000 cells, P1-P1000. My problem is that the matched number in column N may appear thousands of rows below the number in column O and I need to place the "Yes" in that corresponding row. This is where I'm getting stuck.