Thank you!, that was what I ask for..., but I realize I made a mistake in the
question, because I want to delete in column "A" the ones that are NOT
duplicate.
In other words I need to keep the information of the duplicates. Do you know
how can I do that?
Here is the thing I have a lot of data on each row, I work on a spread with
2000 rows, now they gave me the numbers of the ones that they want me to keep
(850) So I put the new column in "B"
If you can help me I would be really apreciate!!!!!
Thank you anyway.



"bj" wrote:

try something like
for your exAMPLE in C1 enter
if(countif($B$1:$B$3,A1)0,A1)
and copy down to C3

"HERNAN" wrote:

I have 2 columns with numbers Column A and B.
I need to COPY on column "C" the ones that are duplicates.
That's it.
(I don't need to find them using conditional formating, I need to copy them)
Please Im gettin crazy with this. THANK YOU IN ADVANCE!!!!

A B
10 30
15 50
20 15