Yes, you can use conditional formatting to format cells based on external data connections in Excel. Here's how:

1. Identify the External Data and Formatting Criteria:

* Locate the cell(s) containing the value retrieved from the external data source.
* Determine the formatting conditions you want to apply. For example, highlight cells with values above a certain threshold, change font color based on specific data categories, etc.

2. Use a Formula in Conditional Formatting:

* Select the cells you want to format based on the external data.
* Go to the "Home" tab and click "Conditional Formatting" in the Styles group.
* Choose "New Rule" from the dropdown menu.
* In the "New Formatting Rule" window, select "Use a formula to determine which cells to format" under "Select a Rule Type."
* In the format values where this formula is true" box, enter a formula that references the cell containing the external data value and compares it to your formatting criteria.

Here's an Example:

Imagine cell A1 holds a value retrieved from an external data source, and you want to format cells in B1:B10 green if the value in A1 is greater than 100.

Your formula in the conditional formatting rule would be:

`=A1>100`

3. Set Formatting for True and False Conditions (Optional):

* Click the "Format" button to define the formatting you want to apply when the formula evaluates to TRUE (meeting the condition).
* You can also set a different format for cells where the formula evaluates to FALSE (not meeting the condition).

4. Click OK:

Once you've defined the formula and formatting, click "OK" to apply the conditional formatting rule. Now, the cells will change format based on the value retrieved from the external data source.

Important Notes:

* Remember that changes to the external data source will automatically update the formatting based on the defined rule.
* Ensure your formula correctly references the cell containing the external data value.
* For complex formatting logic, you can use nested IF statements within your conditional formatting formula.

By leveraging conditional formatting with external data connections, you can create dynamic and visually appealing spreadsheets that react to changes in your data source.