Excel 97/2003 & 2007

I have a sheet which is completed daily by a user.

The rows number about 30 cells (entries) and columns relate to the days of
the month. The day is enumerated in the first column 1 thro 31 (say).
So, to picture it, you have a blank chart with the date listed down the left
and columns named across the top.

Does anyone know of a formula to colour fill the date cell (highlight) if a
number is entered in any of the cells in that row?

TIA for any help.

Ed