If you're looking for an auto-updating EXCEL solution - skip SSRS, and tie a data query directly into your Excel spreadsheet. You can then build your totals, and simply tell it to "refresh the data", and poof - new up to date totals.
Some caveats involved - but should get you a lot closer that what you have going on now.
That's (starting in Excel), Data, Import data, New Database query. Follow wizard.
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Your lack of planning does not constitute an emergency on my part...unless you're my manager...or a director and above...or a really loud-spoken end-user..All right - what was my emergency again?