[amel27]

вариант на AWK:

Код:

@echo off
set $n=50

for /f "delims=" %%i in ('^<list.txt find /v /c ""') do set /a $m=100+%%i/%$n%
for /l %%i in (100,1,%$m%) do set /a $i=%%i& call :sub
:sub
(awk -v S=%$i:~-2% -v N=%$n% "{L+=1;if (L>S*N && L<S*N+N+1) {print $0}}"
) <list.txt >list%$i:~-2%.txt