It is possible to use EDI batch order processing with customer item cross reference numbers

Yes.  You can use customer item number cross referencing with EDI by using the field SZCITM, Customer Item Number.Only one of the item number fields has to be populated, but whatever fields are populated will be validated. Also, if CITM is populated with the customer's item number it must be preceded by the symbol to identify it as a customer item number. This symbol can be located in the branch plant constants. This means if our symbol to identify a customer item number is #  and the customer sends their item number 3003, CITM must be populated as #3003. In