Hi,
you have to define two separate backup specs: one with, lets say 2 weeks retention to pool 'weekly', and one with permanent retention to pool 'monthly'.
First one runs daily except the 1st of each month, the second on runs at 1st of each month.
How to configure the first one , have a look ata Daniel Braun's Blog entry:
http://www.data-protector.org/wordpress/2011/07/data-protector-6-2-scheduler/
Hope it'll help,
Thomas