@echo off&setlocal enabledelayedexpansion

for /f "delims=:" %%i in ('findstr /n ".*" 1.txt') do set num=%%i

set /a num1=%num%-3,num2=%num%-7

for /f "tokens=1* delims=:" %%i in ('findstr /n ".*" 1.txt') do (

  if %%i LSS !num2! echo %%j>>2.txt

  if %%i GTR !num1! echo %%j>>2.txt

  )