If you are referring to the current feedback position of the motor encoder, you can read it from one of the system monitoring registers that is set to hold it.

For example, P0.009 (System Monitoring Register 1) will hold the current encoder position if P0.017 is set to 0 (default).

The encoder position is a 32-bit Int and you would read it from registers 40019 and 40020, in this example.