I want to sum a variable number of rows which is in a column of
numeric information. For example, say the column has entries 1,2,3,4
and 5 in five separate rows. I would like to be able to sum a number
of contiguous entries (e.g. sum the second, third and fourth rows, or
sum the fourth and fifth rows). This can obviously be done by
creating a normal sum function (e.g. =sum(A2:A4) for the first example
above). However, if I want to vary where the series is summed from
(e.g. A2 or A3) - and the number of rows that are summed (e.g. A2 to
A4, or A4 to A5) - I need to go in and manually re-write this formula.
Is it possible to have a sum-type formula linked to two input cells,
where input cell one indicates where the summed series is to commence
from and cell two indicates the umber of rows that are to be summed?

In the csv file below,
A is the column of numeric information
B1 is the first row number of the sum (input cell one)
B2 is the number of rows that are summed (input cell two)
B3 is the sum.

Modify to suit.


-------------- cut here --------------
1,2,start row
2,3,count
3,"=SUM(OFFSET($A$1,B1-1,0,B2,1))",sum
4,,
5,,