::@echo off
setlocal
set counter=10
set filename=%1
set tempfile=%filename%.tmp
for /f "tokens=*" %%a in (%filename%) do call :ADDNUMS %%a
ren %filename% %filename%.orig
ren tempfile %filename%
endlocal
goto :eof

:ADDNUMS
set begin=N%counter%
echo %begin% %* >>tempfile
set /a counter=%counter% + 10
goto :eof