What is the approach we need to follow if we need to copy a list of accounts and its related records from Production to Sandbox
1.)Export the Accounts from Prod as a csv. Keep the 18char id intact 2.) Export the related records as a csv with the Account 18char id intact. 3.) Make a legacyid field on each related object making sure to mark it as an "External ID". 4.) Load Accounts. 5.) Load each object in turn referencing the prod id as the external id for the new record.
I would use the Enabler for Excel, works with Enterprise, Unlimited, Professional and Group. Export your Accounts and other objects you are working with, in Excel with the add-on. Then sign out and sign back into the add-on with your sandbox credentials. From there insert each table into the sandbox