echo var dir=[ > dir.js
forfiles /s /c "cmd /c echo @relpath," >> dir.js
echo ]; >> dir.js

@echo off
setlocal enabledelayedexpansion
set INTEXTFILE=dir.js
set OUTTEXTFILE=dir.txt
set SEARCHTEXT=\
set REPLACETEXT=/
set OUTPUTLINE=

for /f "tokens=1,* delims=¶" %%A in ( '"type %INTEXTFILE%"') do (
	SET string=%%A
	SET modified=!string:%SEARCHTEXT%=%REPLACETEXT%!
	echo !modified! >> %OUTTEXTFILE%
)
del %INTEXTFILE%
rename %OUTTEXTFILE% %INTEXTFILE%