I have 20-odd cells in a row with various numbers. Let's say the first three
numbers are as follows:

A1 100
A2 700
A3 800

I'm trying to find a formula that would search through a range of cells and
find a set of numbers that add up to a specific total, and return the cell
numbers. For example, if I wanted to find a combination of cells that add up
to 1500, the formula would return either the cell numbers (A2 A3) or the
contents of the cells (700 800). Is there any formula out there that does
something like this?