The result of the following formula is 1,396,250; it is found in cell E44:
=LARGE($C$44:$F$44,COUNTIF($C$44:$F$44,"0"))

What function can I use to return the cell reference (i.e., E44) rather than
the amount?

FYI . . . The amounts in the array are as follows, if it matters:
C44 -1650000
D44 -436250
E44 1396250
F44 3575000

Thank you!
Elizabeth