Yeah, I know how to assign addresses using the lines you quoted from the library.
That´s not the problem...
I´m receiving the TX address via serial from a computer and
want to change the TX address before transmitting data also received from the computer via serial.
The address is not hard coded in the arduino, but can change depending on what remote device the computer wants to send data to. As several remote devices shall be used, including all addresses in the arduino code is not feasible.
The data received via serial is the TX address and the payload to transmit both in string format. The payload can easily be converted from string to byte (actually int but in a byte array). The address however is a problem as it has to be converted from string to uint64.
Would it make sense to slice the string and convert it piece by piece to an int and assemble the data to the desired format?