update Customer Bill To Sites Revenue and Receivable accounts

 Hi all,I have one requirement, 
For the Intercompany segment to be defaulted correctly for both the Receivables and Revenue Accounts it becomes necessary to alter the existing set-up in AutoAccounting, as well as to populate the Intercompany segment for the following Customer Bill-To Site accounts         Receivable and   Revenue accounts.
Can some body please let me know where i can i find Customer Bill-To Site accounts         Receivable and   Revenue accounts at customer level in 11.5.10. I know that trasaction level I can find the Revenue and Receivable accounts can be see, but at customer level where it exists.

Also let me know whether any standard API's exists for updating these accounts or not.