Formula for finding a specific sum from a range of numbers?

Is it possible to figure out which combination of numbers in a range would add up to a specific number? Specifically, I have a list of 300 positive and negative numbers, and I know that about 280 of them added together equals 70,000. I just don't know which ones. Any ideas?

Hi,

See the below link for some suggestions.

http://www.tushar-mehta.com/excel/te.../match_values/