Mahmoud offer some AA help with Analytical Accounting Entry (Excel to Dynamics GP) – Free Tool (Beta).
Dynamics GP Essentials: Analytical Accounting Entry (Excel to Dynamics GP) – Free Tool (Beta)
General Ledger & FinancialsExcel & Office
Archived post from 2014. Dynamics GP and the links it points to have changed since; check current documentation before relying on version-specific steps.