Automatically find and highlight common numbers in multiple coulmns.

Hi
I am a crime Investigating Officer and do analyse call detail records (CDR) for investigation purpose. My problem is that I got number of CDRs in a case and I want to know if there is any one or more than one common numbers in these CDRs. In a CDR there are ten to fifteen coulmns and thousands of rows but there are only two coulmns showing calling and called numbers in each CDR. If I paste the data of these two coulmns( calling and called) of each CDR in a new sheet how can I come to know that the number(s) if any in column A&B is also in C&D, E&F etc. or viceversa. Highlighting duplicates by applying conditional formatting does not solve the purpose because there normally exists number of duplicates in each coulmn itself. Please can you help me to find out the common number(S) if any in such given situation.

Thank you for the reply. This formula is showing the result of two coulmns only as true or false. I want to know the common number which may be existing in multiple coulmns. Suppose a number which is existing in coulmns A&B may not be in C&D but in E and coulmn L or a number in coulmn L may be existing in coulmn G and A. I want to identify and highlight these numbers in excel sheet. Could you help me in this situation. Regards.

May I send you the mail, if possible. Here I am not able to attach the file. Thanks.