Highlight your range in Column A

Conditional Formatting
=COUNTIF($B$1:$B$100,$A1)0

Adjust range to suit
format any color you like

"P.hamsa" wrote:

Hi,
I have two columns (Col A and Col B) having the employee numbers.
I want to compare the numbers in both the columns and highlight the
duplicate entries in Col A. Can you help?

Regards,
P Hamsa