automatic creation of new list from values of old list.

Question

one sharepoint list is as follows ListA

colA     colB     
Tim      TimA
Tim      TimB
John     JohnA
John     JohnB
Tim      TimC

how can i automatically create a new list using values of ListA ListB

ColAA    ColBB
Tim      3                           ( because there are 3 items for Tim in ListA) 
John     2

Answer 1

This may not sound proper but the best possible way I see that is to export your lists to excel, do the calculations there and then paste/export the result columns back into a new list in sharepoint. Other than that .NET code or even DataForm XSLT customization (not even considerable due to complexity) for such simple task would be overkill.