MVP Mohammad Daoud and DynamicsInnovations have a product that is free for pasting into the GL. Other modules are available for a price. It's really easy to setup and use.
The product is called Dynamics GP Excel Paste and I covered it in my Convergence sessions.
You can find out more at: mohdaoud.blogspot.com/.../dynamics-gp-journal-entry-paste-from.html
Mark