Yes, it is absolutely possible to use conditional formatting to format cells based on their position within a range in Excel. There are two main approaches you can take:

1. Using the ROW function and comparison operators:

- The ROW function returns the row number of the cell containing the formula.
- You can then use comparison operators like "<", ">", "<=", ">=", or "<>" to compare the row number to a specific value or another cell reference.

2. Using the COLUMN function and comparison operators:

- The COLUMN function returns the column number of the cell containing the formula.
- Similar to the ROW function, you can use comparison operators to check the column position.

Here's an example using the ROW function:

Let's say you want to highlight the first 5 rows of data in a range (A1:A20) with a light blue fill color.

1. Select the range you want to format (A1:A20).
2. Go to the "Home" tab and click on "Conditional Formatting" in the Styles group.
3. Select "New Rule" from the dropdown menu.
4. Choose "Use a formula to determine which cells to format."
5. In the formula box, enter: `=ROW(A1)<=5` (Replace A1 with the top-left cell of your actual range if it's different).
6. Click "Format" to choose your desired formatting (light blue fill in this case).
7. Click "OK" on both the "Format Cells" and "New Formatting Rule" windows.

Now, the first 5 rows (A1:A5) will be highlighted with the light blue fill because their row numbers are less than or equal to 5 as determined by the ROW function.

Similarly, you can use the COLUMN function for conditional formatting based on column position.

Remember, these are just basic examples. You can combine these functions with logical operators (AND, OR) and cell references for more complex formatting rules based on a cell's position within a range.