Remove oldest files in folder by total files count

remove_old.cmd

@echo off
setlocal
set Folder=c:\test\oldfiles
set MaxFiles=3
set FileExt=.png

:start

dir "%Folder%\*%FileExt%" /a-d | find /c "%FileExt%" > NUMfiles.###
set /p count=<NUMfiles.###
echo %count%

set OldestFile=
for /f "delims=" %%a in ('dir /b /o:d "%Folder%" 2^>NUL') do (
	set OldestFile=%%a
	goto Break
)
:Break
if %count% LEQ %MaxFiles% (
	echo No old files!	
) else (
	del "%Folder%\%OldestFile%"
	goto start
)