Try the below with

A1-sheet name
A2-top row number
A3-top column number
A4-bottom row number
A5-bottom column number


=SUM(OFFSET(INDIRECT("'" & A1 & "'!A1"),A2-1,A3-1,A4-A2+1,A5-A3+1))

--
Jacob


"Hershmab" wrote:

I have a series of cells containing the defining limits of a range, i.e.:
-sheet name
-top row number
-top column number
-bottom row number
-bottom column number

How do I sum (or otherwise operate on) the array so defined? I have tried
formulae containing combinations of various ADDRESS and INDIRECT functions,
but have not yet come across one that works.