Let's suppose you're starting in row 1. Then select cell B1 and set your
conditional format for this cell: Format Conditional Formating. Choose
'formula is' in the first drop-down, and enter the formula =($B1$A1). Click
Format and choose the appropriate settings (pattern, font, etc). Finally
click OK.
Then select all the cells to which you want to apply similar conditional
formatting and hit ctrl+Y (repeating the prior change, in this case the
conditional formatting).

"Mish80" wrote:

Hello -

I have two columns with different numbers in each. Let's call them column A
and column B. When column B is greater than or equal to column A... I'd like
to make it red. Unfortunately, I'm having trouble selecting multiple cells
to apply this to. I can only make it work one at a time... or referencing a
whole column to one number, rather than the other column.

I keep getting the error message:
"You cannot use a direct reference to a worksheet range in a conditional
formatting formula. Change the reference to a single cell, or use the
reference with a worksheet function, such as =SUM(A1:E5).

Your help is greatly appreciated.

Thanks!