Avoiding massive nested if statements - choose different column depending on month

Hi.

I have a summary sheet on a financial spreadsheet. I am trying to avoid complicated nested if statements which are prone to error and difficult to update.

What I have on the summary tab is, for example, 6 different columns which index match/lookup data from another sheet. The other sheet contains in column A, a unique identifier for all the production locations of the business. There are then a series of columns, each of which is for a different product and month. For example, column b-m are volume of Product 1, for months Jan-Feb in 2012. The next 12 columns would be for Product 2 volume, for months Jan-Feb. My summary sheet then index/matches based on the unique identifier. I update the summary tab each month.

What I would ideally like to do, is to change just one cell on the summary tab, which would say "August" or some indicator of the month that we're in (could be a number instead). This will then go and grab the appropriate column on the other tab.

Any ideas how to do this by avoiding a massively complicated if statement?

See example:

Ideally I'd like to be able to just change that highlighted cell to, say, May, and the formula changes to index(Detail!F:F...etc.) instead of having to do this manually/with a massive if statement (for many different products).

Looks like I've got you guys stumped?

Hi. Looks good. But how do I omit the product choice aspect? The thing is, I am going to display many products in columns next to each other, so I don't really need that flexibility within a cell. So, really, I think I just need that extra match bit, to match the month up. So how do I do that?

Alternatively, how do I expand the formula to incorporate n products? I would probably not want this, though, because I prefer less complicated formula that I can get my head arou