We need to correct our chart of accounts (change 350-some account codes from four digits to a nine-digit code) by the end of the month, no questions asked.  Key questions:
 
1) AM-H Change G/L Account Codes will make the change only if the new account code is already entered into DBA.  We see two choices.  Either enter the 350 new accounts in through AM-C Enter General Ledger Accounts or try to import the 350 accounts in through DE-G Import Chart of Accounts.  Using the DE-G should be much quicker.  My question is then: can we import JUST the 350 new accounts through DE-G, leaving intact in the chart of accounts the existing account codes?  Or will DE-G force us to import all new AND existing accounts (which could adversely affect the general ledger operation)?
 
2) If we can import, can we import the new codes in with the additional 4-digit department code, or do those codes need to be added through AM-D?
 
3) Once the new codes are in, are properly changing account codes as simple as using AM-H and changing the default settings in AD-A?  That is to say, what do we need to look out for?  We would like the G/L codes to change for 2001 and 2002 G/L activity, change in all open PO, work order, inventory, sales order, A/R and A/P activity as well as closed work orders, sales orders and POs  (we have not archived any of our DBA files into the DBA historical files).  Or will this process evolve into a massive hand-edit in the G/L data files?
 
Thanks!
Mike

1.  Actually, Lorne is mistaken.  If you import the Accounts, it will append to the existing file.  It will only replace existing account numbers.
 
2.  Yes, you can import the new codes with the departments
 
3.  Yes, so long as you do both steps.  Change the existing data to transfer to the new account and change the defaults so subsequent postingd also go to the new account.