impk

@echo off
setlocal enabledelayedexpansion
(
set "s=^!x^!"
set x=2
set ss=abc
echo 01 %s% 
echo 02 !s!
echo 03 %x%
echo 04 !x!
echo 05 %ss%
echo 06 !ss!
)
echo 07 %s% 
echo 08 !s!
echo 09 %x%
echo 10 !x!
echo 11 %ss%
echo 12 !ss!COPY

用这个代码查一下
01=空  02=!x!  03=空  04=2  05=空  06=abc
07=2  08=!x!  09=2  10=2  11=abc  12=abc
然后看懂前三层不成问题