The linksync eParcel solution does not support applying more than one Charge Code to a shipping method.
- You want to apply Express Post to orders in deliveries one state, but not others in Australia.
- You want to apply the same shipping type to domestic and international destinations.
In use cases like these you must configure Magento to apply different shipping methods to those orders. ie. have state-based shipping rules, or country based shipping rules, and then assign different Charge Codes to each of those shipping rules.