So u need to create a program in order to copy the data for source sales area to target sales area for a certain customer?
If it's so u can create:
- or porgram in order to prepare a file for std BI RFBIDE00,
- or a BDC program to simulate the transaction VD01: here u can indicate a sales area as reference from to pick up the data to be copied in the target sales area.
- or program uses the BAPI_CUSTOMER_CREATEFROMDATA1, here u can assign a sales area as reference
For the maintenance of customers, there is NO BAPI and NO direct function module.
There are some functions modules that looks like providing the functionality and where the name is looking nice. But these should not be used. The existing BAPIs or FM like the aboves ones have been designed for a very specific case. Despite the names, they should not be used out of their initial context: eg: Online store or consumers maintenance.
Below ECC 2005 (6.00), the only solution was batch input and DEBMAS idocs. See [note 384462|https://service.sap.com/sap/support/notes/384462]
Starting with ECC 2005 (6.00) and above: a synchronisation tool has been introduce. See class CMD_EI_API and VMD_EI_API
In your case, you may use:
the above classes
LSMW with batchinput or DEBMAS idoc
XD99 / XK99 for mass changes
Hope this helps