Create formulas on specialized Excel Document for me.

My company uses several online spreadsheets to track orders and inventory levels. There are three spreadsheets on Google Docs with the data you will need for the Excel document. I have already created an Excel file that has three sheets on it. Each sheet contains live data from one of the three Google Doc spreadsheets. This data is updated by my company every day, and the updated data automatically updates itself on the Excel document as well. I already tried to make this document with Google Docs, but it is to large for Google Docs and does not work well, so I am choosing to do it with Excel which does not have the same limitations. I can supply you the Excel document that already has the three sheets with the live data on it. Here is the data types supplied by the three sheets: #1 a list of every item's name, manufacturer, and item-number (SKU), plus a column that combines the SKU, manufacturer, and product name together. This list will grow over time, so the excel document must use this data dynamically. #2 a list of every order, which includes the Date, SKU, and Quantity, and Category Number. New orders will appear every day. #3 a list of every item that is received into inventory to restock supplies. This includes date, SKU, and quantity received. I need a document that tracks the sales every day, starting from 1/1/2012, and continuing into the future. I call this a "Sell-Through Rate" spreadsheet. The document needs to use the data on sheet #3, so that the document will know if an item is sold out. Since we sell hundreds of different items, I would like there to be additional sheets that show only the "Sell-Through Rate" for items with a certain Category Number, or items by a certain manufacturer. If you would prefer not to create the additional sheets, then I should be able to create the additional sheets once you have created the main sheet, by copying/modifying your formulas. It would be great if this document could also show a graph of sales by item, or by category number/manufacturer if that is easier. I can modify the live data slightly if you need me to.