In this post, I want to talk about Application Object in Microsoft Excel, that lets you work with Excel sheets programmatically.
You could write code such as follows:
Application.Windows("book1.xls").Activate
or
Set x1 = CreateObject("Excel.sheet")
x1.Application.Workbooks.Open "newbook.xls"

You also have a PivotTable and PivotChart object in the Excel Object Model.
They facilitate pivot transformation of data. You could use the PivotTableWizard to generate the PivotTable.
ActiveSheet.PivotTableWizard(xlDatabase, Range("A1:C100")