First, apologies if this has been answered before but I couldn't find
anything close in the forums:

My problem is I need to find the first row reference if a value in one
of the columns is (unpredictably) less than 0. I have tried a mix of
Index, Match and the Excel lookup wizard but to no avail.

For example, at its simplest I have 2 columns x and y

A B
1 x y
2 1 13
3 2 6
4 3 0
5 4 -1
6 5 -12
7 6 4
etc

how do I locate the first row when the y column goes negative. I know
it is simple if I know beforehand ( in this case it is row cell A5) ,
but if the Y column varies at random, I get stuck. Any help much
appreciated
Bob