An improved Alternate Modified Forms and Reports Window is the latest GP2013 Feature of the Day.
Feature of the Day: Alternate Modified Forms and Reports Window – Inside Microsoft Dynamics GP – Site Home – MSDN Blogs
Reporting & BITips & Hidden FeaturesMicrosoft & the GP EcosystemGP 2013
Archived post from 2012. Dynamics GP and the links it points to have changed since; check current documentation before relying on version-specific steps.