How to define a range in calc as start cell and number of cells?

[tpollak]

A1 contains =sum(B2:B4)
A2 contains =average(B2:B4)
A3 contains =sum(c2:c4)

Column B  Column C
Header      Header
value 1      value 1
value 2      value 2
value 3      value 3
value 4      value 4

To simplify I would like to do something like A4 contains 3

A1 =sum(B2 ?A4)
A2 =average(B ?A4)
A3 =sum (C2 ?A4)

so I easily can change the range by changing the content of A4.

Is something like this possible? If so, how?

[Lupp]

There are the functions INDIRECT(), OFFSET(), and sometimes also useful in related cases, ADDRESS().
The most flexible of the applicable functions is OFFSET().

[tpollak]

Offset does exactly what I want to do. Thanks for the help.