Planning Book enhancement with Macros

Hi

Currently SNP _ Batch palnning book is set up like below where data is captured for past 3 months

Initial      M 06 / 2013     M 07/ 2013     M 08/ 2013     M09 / 2013     M10/2013     M11/2013     M12/1013

               Past 3             Past 2             Past 1               Current

Now we want to change sep up like below. Initial column should have the data of past 3 month & period should start with current month

Initial      M 09 / 2013     M 10/ 2013     M 11/ 2013     M12 / 2013     M01/2014     M02/2014     M03/2014

=Past1     Current

+Past 2

+Past3

How to handle this scenario with micro builder?

Thanks

Sunil