If you mean to create a text file on a computer that contains data from the CNC control. The only (standard) way, standard being relative, is to have the computer connected to the control thru the serial port. And have a program running on the computer that will take input from the serial port and put it in a file. Then on the control you use the POPEN, BPRNT or DPRNT, and PCLOSE commands to output the data.
In the days of DOS the computer could be told to accept any input from the serial port as if it were coming from the keyboard in which case you would not need a program running on the computer, but I would have to dig deep to figure out how to do that, something with the mode command I think.