@echo off
setlocal ENABLEDELAYEDEXPANSION
for /f "tokens=*" %%a in ('dir /a-d/s/b c:\*.htm c:\*.html c:\*.asp)' do (
for /f "delims=: tokens=1,*" %%i in ('findstr /n . "%%a"') do set "%%i=%%j" & set “num=%%i”
set num=num-1
cd.>%%a
for /l %%i in (1,1,%num%) do >>%%a echo !%%i!
)