I'd try one of two methods. First, use the MS Windows "scheduler" to
fire off you spreadsheet at midnight (make sure to leave the computer turned
on) and have a VBA macro triggered when the workbook is opened to perform the
data movement. A second, albeit more difficult method, would be to write VBA
code to structure an internal timer that would watch for midnight. In this
case, you'd have to open the workbook before going home for the day, and
activate the macro that sets up and runs the timer.
Steve in Ohio