I am using W98 and Excel 2K 9.0

Question 1.
On my sheet I print the column letters and row numbers. I have cells
that contain comments such as 'Total of Rows 5 To 8' or 'Row 15 Less
Row 23'. The numeric portion of these comments, 5, 8, 15 and 23,
represent actual row numbers. If I insert or delete a row it now makes
the comments wrong and they must be changed. Is there a way to
structure these comments so the numeric portion is a variable that will
change as rows are inserted or deleted?

Question 2.
I have a column, say column C, where rows 5 to 10 contain numeric data.
Row 12 contains the formula =Sum(c5:c10). This works fine. Sometimes
when I insert a new row, say 8 or 11, the formula in what is now row 13
will change to =Sum(c5:c11) and sometimes it will not. I am unable to
determine those conditions what conditions are controlling this action.
Can someone shed some light on this?

Thanks for any and all help.