skuny

@ECHO OFF
goto end2
:end2
set str1=你他娘的是谁？他娘的我不告诉你。
set str2=你他娘的到底是谁？我他娘的还就不告诉那个他娘的你。
set a=%str1:他娘的=tnd%
echo %a%
set a=%a:tnd=%
echo %a%
set b=%str2:他娘的=tnd%
echo %b%
set b=%b:tnd=%
echo %b%
pause>nul

skuny

@echo off
setlocal enabledelayedexpansion
for /f %%i in (a.txt) do (
set a=%%i
set a=!a:他娘的=tnd!
echo !a!
)
for /f %%i in (a.txt) do (
set a=%%i
set a=!a:他娘的=!
echo !a!
)
endlocal
pauseCOPY