I want to create a formulae that dynamicaly alters the row references of a
SUM function nested within a INDIRECT function based on a start and end date
variables.

In order to to this I need a lookup that returns the row number and/or cell
adress of the first cell that matches or exceeds the date variable and
utilises the result in a SUM function nested within the the INDIRECT formulae
(If possible I want to avoid inserting an additional column in the original
data table that calculates the row refrence to be used with a simple vlookup)

Any help offered would be appreciated

Kind Regards
Andrew