Is it possible to have the data in a cell on one worksheet automatically copy
itself to another worksheet in the same document?

For example, if I have seperate worksheets for each week in a month listing
income for each day of that week, and the total income for that week tallied
up...can the cell containing the sum for that week be automatically copied to
a seperate worksheet where the weekly totals are being compared to each other?

That way if I change a daily amount, it will not only update the total for
that week on the weekly worksheet...but also update the weekly total on the
monthly worksheet.

It seems like this would be a very useful function, but I haven't found any
information on whether it is possible and how to accomplish it.

Thank you so much for any suggestions...it is driving me nuts! :)