Excel 2007 VBA: building a table from various spreadsheets?

[zeno1]

I try to build a column in sheet2 with source data from another sheet.

example:
ColumnA(Sheet1) | ColumnA(Sheet2)

Title A | Title B
12.1
43.8 | Average(A2:A3)
8.7 | Average(A3:A4)
6.5 | Average(A4:A5)
7.4 | Average(A5:A6)

I'd like to write Title B and then the averages in VBA (not directly in Excel).