Summing similar items

Hi - I assume that this will require a macro if not please forgive a newbie.


I have an excel workbook that will contain about 20 worksheets. The 20 sheets are similar in layout but have different numbers of rows and different numbers of column repeats (see below).

Each spreadsheet has less than 1000 rows and 32 to 44 columns.

There are 3 columns that repeat between 4 and 8 times.

These 3 columns are: item, quantity (for each product) and total items per product (total items is calculated).

Each item may be in any one of the repeats.

I would like to be able to sum the total items per product of all items with the same name within a selected area and within the whole sheet. These sub-totals I'd like to keep on the sheet with the other information but at the side as a list of items and the sub total for each item.

I'm a newbie to excel and don't have a clue where to start to do this.

I'm sorry if this description isn't completely clear and that the attached part spreadsheet helps. Please ask me and I'll try to clarify specific points.
I'd greatly appreciate some help.