Conditional Formatting

[greenchk]

I have data in three columns. I want the rows to highlight if the data in one
row matched all three columns of another row:

For example:

1 21N 16W no highlight
1 21N 18W no highlight
1 22N 15W highlight
1 22N 15W highlight
1 22N 15W highlight

Thank you for your help.

 

[Luke M]

Selecting a cell in row 1

Format-Conditional Format
formula is:
=SUMPRODUCT(--($A$1:$A$100=$A1),--($B$1:$B$100=$B1),--($C$1:$C$100=$C1))>1

Adjust range sizes as necessary. Note that you can't callout entire column
in SUMPRODUCT unless using XL 2007.