Modbus combining two registers

Hello,
I need to get the result of reading two registers:

With ModbusDoctor the result is correct, but how can I get the result using home assistant?

It might work like the following syntax:

- name: "Usage Water"
  unique_id: "water_usage"
  address: 1583
  data_type: uint32
  input_type: input
  count : 2
  scale: 1
  precision: 1
  slave: 1

Register 1583 contains: 2324
Register 1584 contains 1
combined should return: 67860

I tryed using data_type: custom but didn’t get the right result. What do I have to do?