@echo off
setlocal enabledelayedexpansion
for /f "delims=" %%i in ('dir /b /s /a-d *.html') do (
set "f=100%%~ni"
echo !f!
set "f=!f:book.=!"
echo !f!
set "f=!f:~-3!.txt"
echo !f!
ren "%%i" "!f!"
)
@echo off
setlocal enabledelayedexpansion
for /f "delims=" %%i in ('dir /b /s /a-d *.html') do (
set "f=100%%~ni"
set "f=!f:book.=!"
set "f=!f:~-3!.txt"
ren "%%i" "!f!"
)