setlocal enabledelayedexpansion
set dname=%date:~0,4%%date:~5,2%%date:~8,2%
set n=%cd%
:loop
if not "!n:\=!"=="!n!" set n=!n:*\=!&goto loop
set num=0
for /f "delims=" %%a in ('dir /b /on /a-d *.txt') do (
set /a num+=1
set fileex="%%~xa"
ren "%%a" !dname!!n!_!num!!fileex!
)