Production Summary using excel 2003

[Matt]

I have established a master invoice and 20 Store invoices that add up into a
Production summary per ITEM per week.
I now have been requested to develop a daily summary, per day, per date per
STORE, per item.
I need excel to recognize the day, the date, and then the production list
from the STORES, into this summary. And I haven't a clue which way to turn.

I can share the spreadsheet to make this clearer...
Matt