Hi,
I am aware of this great functionality.
Let me explain.
I have data in this format (example):
Person, Product, Region, 1.1.2010, 2.1.2010, 4.1.2010, 7.1.2010 (HEADER)
Luka, hammer, Reg1, 234,443,2322,333 (LINE ITEM, Where numbers are Sales on the DATE)
Hui, hammer, Reg2...