./src/qt/bitcoin-qt bchreg:qrxvv8fpv42wvlls6z4mp9qvrs3kar2pau5tssl8xd?amount=42.00000000&label=test1&message=a%20message
./src/qt/bitcoin-qt bchtest:qp5dzwdct8xcpec62z799rdfpylxftsl6v0trfz2m9?amount=42.00000000&label=test2&message=a%20message
./src/qt/bitcoin-qt bitcoincash:qrc5xvnqwv3esj8hs5w85gh3xjwgnnjfvv3ll6wmdu?amount=42.00000000&label=test3&message=a%20message
Observe that the client starts on the right chain, and inputs correct values into "Send" dialog.
./src/qt/bitcoin-qt "bitcoincash:qrc5xvnqwv3esj8hs5w85gh3xjwgnnjfvv3ll6wmdu?amount=42.00000000&label=test3&message=a%20message" "bitcoincash:1F6MqpCw3f8JRErcZMYjkFLBzpFvvjobZZ?label=two%20addresses"
Observe that the client starts on mainnet, and inputs correct values for both addresses in "Send dialog"