I create a new spreadsheet every week that tracks employee tips. Each
employee has their own sheet in the workbook, and each week has its own
workbook. The employee sheets have their hours worked each day of the week,
their tips calcualted for the day, and their tip total for the week.

I want to create a formula that keeps a running total of employee tips
throughout the year (YTD Tips). I create the current weeks sheet by opening
the previous week and replacing the information. Let's say the Weekly Tips
cell is A10. I want A10 added to the YTD cell everyweek, and to update
automatically every week. Is that possible? Hope I explained it ok. Thanks
for any recommendations.