How do I sum a column of values when rows are inserted or deleted outside the formula?

[Aretesys]

If I have a spreadsheet that sums a column of the rows above it, I obviously have to refer to the starting row/cell, say A3. I then refer to the ending row/cell, say A10.
My problem is that my users will insert new rows above row 3, but my formula says start at A3. If there is a value to be summed in A2, it's ignored because the formula starts with A3.
The same problem occurs when the users insert a row below row 10; the value in row/cell A11 is ignored. I know Excel can adjust if they insert a row in between the values in the formula, for example a new row above row 6. But they can't be counted on to do that, despite my entreaties.
I don't want a VBA solution; I'm sure there is a function I'm missing. I've looked at Dynamic Ranges, but I don't think that solves my problem.
So how can I sum all the rows that have user data without checking the formula each time I publish the spreadsheet?
I'm using Excel 2007, but will be switching to 2013 in a day or two.
I know this has to be one of the dumbest questions on the forum!
Thanks so much for your help!

 

[Aretesys]

Thanks for your reply skorpionkz, but I'm afraid I don't understand what you're saying. Are you asking something about the range not including totals?
And the second sentence doesn't make sense, but maybe I'm reading it wrong. Did you mean not instead of hot?