Is there any way to copy all accounts with the second segment being 01 to then insert the same GL account number with the second segment 03?<br/>
EX. 10000-01-00 copied to 10000-03-00 but I want to do this with all the G/L's. Is this possible or is is an manual process?<br/>
You can use the account code generator tool (Financials>Account code generator) to create the different segments but in the scenario you described you already have some segments defined, and you would like to copy it over to other segments.
One option would be, to export you chart of account to Excel, add the additional accounts and use Data transfer workbench to bring it back to SAP Business One.