sum array depending on vertical & horizontal references

Hey guys,

I have a big issue I need to do a sum of an array based on 3 horizontal references (Year, Month, Week) and 1 vertical references (a financial line such as Sales or Profit).
Basically I want to do the sum of Sales for a week by summing up Sales on Monday + Sales on Tuesday +...+ Sales on Sunday. And to do that due to the special arrangement of the table I have to input the Year, the Month and the Week number and the financial item(in this case Sales). I need to do this with formulas since it needs to be dynamic. I know it's easier to do it with pivot table but i cannot. have a look at the image and at the attachment

Excel Capture.PNG