1. Select the cell or range of cells where you want to apply the conditional formatting.
2. Go to the Home tab in the ribbon and click on Conditional Formatting in the Styles group.
3. Choose New Rule from the drop-down menu.
4. In the New Formatting Rule dialog box, select Use a formula to determine which cells to format.
5. In the Format values where this formula is true field, enter your if logical function. For example, if you want to highlight cell A1 if it contains the value "Yes", you can enter the formula
   Formula:

   =A1="Yes" 

   (without the quotes).
6. Click on the Format button to choose the cell fill color you want to apply.
7. Click OK to close the Format Cells dialog box.
8. Click OK again to apply the conditional formatting rule.

Now, whenever the if statement in your formula returns a true response, the corresponding cell will be highlighted with the cell fill color you chose. You can also customize the formatting options further by adding additional rules or modifying the existing ones.