http://www.getafreelancer.com/projects/Find-Target-Sum-EXCEL.html
There was the trial project, and it was expired.
The goal was to make the high speed algorithm to find the set of numbers more closer to the target sum. I made the Delphi application solving this task with 100% precise (and many variants of the target set of rows).
Here you can download the Demo Application with restriction of first 1000 records: http://yetidi.net/files/TargetSumDemo.zip.