How to reverse a meter reading in a program

I am trying to reverse a meter reading in a similar way as:

T-code EL37

--> Writing installation --> Executing

--> Selecting reading --> Reversing

but instead of using the transaction, doing it directly in a program.

I made some research and found these FMs:

ISU_METERREAD_CANCEL, ISU_O_METERREAD_OPEN

but I haven't been successful in reversing the meter reading using these FMs.

Does anybody knows what to pass to these FMs or any other FM to reverse a meter reading, or how to reverse a meter reading (in code)?

Thanks.