Report Designer - Footer Calculations

I have a report that has the MIN and MAX values reported in the table.

These values appear in the footer OK.

What I need is to calculate the difference between the MIN and the MAX and display the value also.

How do I enter a formula in the footer.

Thanks.

My cell in the footer contains the following

@min.U1_mw_hr_mtr@
@max.U1_mw_hr_mtr@

@max.U1_mw_hr_mtr - min.U1_mw_hr_mtr@

You can add expressions within the @ characters. That’s also how you do functions (including the running totals).