I am running a yearly total for a weekly average on a new worksheet
every week as follows:

=AVERAGE('6-23-05'!F18,'6-30-05'!F18,'7-7-05'!F18,'7-14-05'!F18,
'7-21-05'!F18,'7-28-05'!F18,'8-04-05'!F18,'8-11-05'!F18,F18)

When I copy the blank template to add a new week, I have to manually
add the cell of the previous week to the equation. Is there a way to
automate this? Eventually, this value is going to get incredibly long,
so I'm thinking there must be a better way.

Obviously I'm not terribly bright when it comes to Excel, so any help
would be appreciated.

Thanks,
-John