Microsoft Excel Advanced Help Needed

I need an experienced Excel developer to solve a problem for me.

We currently have an incoming delivery forecast file on our server that shows us all our incoming deliveries of stock for the year.

We need a way to import that data to another stock forecasting sheet that provides the number of incoming units per week and the sales for each SKU that we sell. It is slightly more complicated as some SKUs come in in more than one format. Basically, to solve the problem, lookups need to be done to calulate the volume of incoming stock per week from our stock in file and put it in the stock forecast sheet.