While you can't directly use conditional formatting to highlight specific sums in Excel, you can achieve a similar outcome by combining the SUM function with other formatting options. Here are two methods:

Method 1: Using Conditional Formatting Based on Formula

1. Calculate the Sum: In a separate cell, enter the formula to calculate the total you want to track (e.g., `=SUM(A1:A10)`).
2. Apply Conditional Formatting: Select the cell containing the sum formula.
3. Go to the "Home" tab and click on "Conditional Formatting" in the Styles group.
4. Choose "Format Cells Based on a Rule" from the dropdown menu.
5. In the new window, select "Format values where this formula is true" under "Select a Rule Type."
6. In the "Format values where this formula is true" box, enter a formula to compare your sum to a target value. Here are some examples:
- Highlight sums greater than a specific amount: `=A1>1000` (Replace A1 with your sum cell address and 1000 with your target value)
- Highlight sums within a range: `=AND(A1>500, A1<2000)` (This highlights sums between 500 and 2000)
7. Click the "Format" button and choose the desired formatting for highlighted cells (e.g., fill color, font color).
8. Click "OK" to close all the dialog boxes.

Now, whenever the sum in your formula changes, the formatting will automatically adjust based on the defined condition.

Method 2: Using Nested IF Statements and Formatting

1. Calculate the Sum: Similar to method 1, calculate your total in a separate cell.
2. Use Nested IF Statements: In another cell, enter a formula using nested IF statements to check the sum and apply formatting based on the condition. Here's an example:

`=IF(A1>1000, ""&A1&"", A1)` (This formula displays the sum in bold if it's greater than 1000, otherwise it shows the regular value)

Note: The "" symbol creates bold formatting within the formula itself. Adjust the formatting codes and conditions within the IF statements according to your needs.

3. Apply Formatting to the Formula Cell: Select the cell containing the nested IF formula and apply the desired default formatting (e.g., font style, color).

This method allows you to display the formatted sum directly within your worksheet.

Both methods achieve the goal of highlighting specific sums visually. Choose the method that best suits your preference and spreadsheet layout.