Yes, it is possible to use the active cell in an Excel formula. This can be done by using the cell reference of the active cell in the formula.

For example, let's say you want to add the value of the active cell to the value in cell A1. You can use the following formula:

=A1+ACTIVECELL()

The ACTIVECELL() function returns the cell reference of the active cell. This function can be used in any formula where you want to reference the active cell.

To display the result of the formula in a cell at the top of the spreadsheet as you scroll, you can use the following steps:

1. Select the cell where you want to display the result of the formula.
2. Enter the formula that references the active cell.
3. Click on the View tab in the ribbon.
4. Click on Freeze Panes.
5. Select Freeze Panes from the dropdown menu.
6. Scroll down your data and see the result of the formula in the frozen cell at the top of the spreadsheet.

By freezing the panes, the cell at the top of the spreadsheet will remain visible as you scroll through your data. This will allow you to see the result of the formula based on the active cell as you move through your data.