hi, Eric !

not sure if I'm following you accurately, but you could try as first approach w/ the following (CSE) array formula:

[D1] =max(offset(a1,,,match($g$1,subtotal(9,offset(c1,, ,row(indirect("1:20")),)))+1,))

hth,
hector.

Does anyone have any suggestions on how to determine the values under following conditions?
Under column A, there is a list of numbers.
Under column C, there is a list of numbers.
There is 145 in cell G1.

Starting to sum from C1 to bottom, if the sum from C1 to C9 < 145 in cell G1
and the sum from C1 to C10 = 145 in cell G1, then return highest number from A1 to A10 into cell D1.

For the next number
Starting to sum from C2 to bottom, if the sum from C2 to C9 < 145 in cell G1
and the sum from C2 to C10 = 145 in cell G1, then return highest number from A2 to A10 into cell D2.

Does anyone have any suggestions?
Thanks in advance for any suggestions
Eric