Can someone help please!

I would like to format cell colors based on values that are in the cell. The
numbers in the cells are alpha-numeric order numbers followed by a number of
days in the sytem (e.g. x12345678-14). Some cells have up to 14 "orders" in
it.

How can I conditionally format the cell if the number of days is between
7-14 (green), 15-24 (Yellow) or 25 (red). I am using Office 2007.

Thanks in advance!
-Rob