Как в текстовом файле удалить все строки, начиная с первой, до строки, соответствующей определенному значению?

@echo off
SETLOCAL EnableDelayedExpansion
 
set SRC=file.txt
 
for /f "usebackq delims=" %%a in ("%SRC%") do set endstr=%%a
echo %endstr:~0,11%>new.txt
pause

@echo off
setlocal enabledelayedexpansion
for /f "usebackq tokens=*" %%A IN ("1.txt") DO (set cifra=%%A&set cifra=!cifra:~0,11!)
for /f "usebackq tokens=*" %%A IN ("2.txt") DO (set cifra2=%%A&set cifra2=!cifra:~0,11!)
if %cifra% LSS %cifra2% (set cifra=%cifra2%)
call :ReadTo 3.txt string count
(for /L %%A IN (%cifra%,1,%count%) DO (echo.!string.%%A!))>3.txt
echo.All
pause>nul
 
:ReadTo
for /f "usebackq tokens=*" %%A IN (`find /C /V ""^<"%~1"`) DO (set %~3=%%A)
(for /L %%A IN (1,1,!%~3!) DO (set %~2.%%A=&set /p %~2.%%A=))<"%~1"
exit /b

more +%cifra% <3.txt >4.txt& move /y 4.txt 3.txt

@echo off
setlocal enabledelayedexpansion
for /f "usebackq tokens=*" %%A IN ("1.txt") DO (set cifra=%%A&set cifra=!cifra:~0,11!)
for /f "usebackq tokens=*" %%A IN ("2.txt") DO (set cifra2=%%A&set cifra2=!cifra:~0,11!)
if %cifra% LSS %cifra2% (set cifra=%cifra2%)
call :ReadTo 3.txt string count
(for /l %%A IN (1,1,%count%) DO (
 if "!copymode!"=="1" (echo.!string.%%A!)
 if "!string.%%A!"=="%cifra%" (set copymode=1)
))>3.txt
pause>nul
exit /b
:ReadTo
for /f "usebackq tokens=*" %%A IN (`find /C /V ""^<"%~1"`) DO (set %~3=%%A)
(for /L %%A IN (1,1,!%~3!) DO (set %~2.%%A=&set /p %~2.%%A=))<"%~1"
exit /b