Replacement item in sales order entry

 In sales order entry, if a particular item is entered, I want the replacement item to populate the detail line. The customer master record flag to accept substitutions is set to "Y". An item cross reference entry is added to associate the item with its replacement (type code = R). P4211 processing option for replacements is set to "R". Is there anything else that needs set up to do this? Is the order entry procedure the same?

Thank you!!