[sov44]

Код:

@echo off
SETLOCAL EnableDelayedExpansion
 
set SRC=file.txt
set DST=out_#.txt
set DLM=--- ---
 
for /f "tokens=1* delims=]" %%a in ('find /v /n "" ^<"%SRC%"') do (
if not defined $F (
  set /a $N+=1& set $F=F
  set "$O=%DST:#=!$N!%"
  type nul >"!$O!")  
if not "%%b"=="%DLM%" (echo.%%b>>"!$O!")
if "%%b"=="%DLM%" set $F=)