I have custom account numbers in my Zoho CRM Accounts module after migrating over from another CRM system; they are in a single line field but only contain a numeric string.  I'd like not to lose this history but create an auto-number field from a particular starting point going forward in Zoho CRM Accounts.  I'm told that I cannot create an auto-number field and import previous data for it thus I believe what I may need to do is create a formula to copy an auto-number field over to my current account number field upon Account creation.  Any advise on this situation would be appreciated.