On the heels of his look at Word Templates, Mariano also looks at Debugging Microsoft Dynamics GP 2010 Word Templates. Somehow I think that one post led to the other but that’s just me.
Debugging Microsoft Dynamics GP 2010 Word Templates
Excel & OfficeInstall, Upgrade & AdminGP 2010
Archived post from 2010. Dynamics GP and the links it points to have changed since; check current documentation before relying on version-specific steps.