Text data concatenation in Pivot?

Hello,
I need to consolidate text data in a pivot table.
I just can not find a way to do this as only numerical functions appears to be possible in pivot.
Eg:
Year Level textData
2006 High Text_A
2006 High Text_B
2007 Low Text_A


I would like to get the 3 following lines:

A1: B1: 2006 C1: 2007
A2: High B2: Text_A\ntext_B C2:
A3: Low B3: C3: Text_A


Any help greatly appreciated!