Using HA energy dashboard values elsewhere in HA

Hi,
I’d like to create a custom sensor that takes my total daily consumption and subtracts all of the individual devices I am monitoring to show me the remaining consumption. So how much of my energy consumption is unaccounted for.

To do this I want to take the current energy consumed today, and subtract the daily consumption for all of the other devices I am tracking. Then I want to add this sensor to the list of individual devices I am monitoring.

The issue is that it seems that all of these sensors are internal to the Energy dashboard, and cannot be found in my entities. Am I going about this in the wrong way?

Advice would be greatly appreciated.

Thanks,
Bastiaan