Writing text to a file is just as easy as writing text to screen. Open the file, redirect the output, and write like you would write to the screen:

     64 string filename
     " outfile.dat" filename copy

     output open                     \ open the file
     0= if                           \ error if not open
           ." File could not be opened" cr quit
     then

     output file                     \ write to file
     ." This is written to disk" cr

Just note that 'CR' will always write a linefeed, even when issued under a Microsoft Operating system.