Has anybody experienced a situation where a smart tag or something like it is used to tag data which can be found and indexed by another excel sheet? For instance, if I had 10 excel sheets talking about the price of tomatoes each week and I tagged the total price in each of the 10 documents with "total tomato price." Could I use some sort of function or macro to get all of the total tomato prices for each week indexed in a column on another excel sheet?

So my general questions are:
Is there an efficient way to create a database only using excel?
Does this sound viable?