I've got a data table that has a number of columns for data from two years. Each sample from each year has its own ID, but some individual samples from the first year (let's say "A") represent multiple samples from the following year (let's say "B, C, D, E, and F") and vice versa. The trick is to sum B, C, D, E, and F so I can compare that number to the number I have for A. I can perform the summations manually, but I have a lot of data (nearly 100 "duplicates" I think).
Is there any Excel-fu that anyone knows on how to accomplish this? I've been scouring the internet, but I'm afraid it's either not commonly done or not done with any sort of scripting. I'd be grateful for any ideas. Thanks!