set x=vhi
set y=vmdk
echo off & cls
for /f "delims=" %%a in ('dir /b/a-d %~dp0') do (
setlocal enabledelayedexpansion
set source=%%a
if /i "!source:~-4!"==".%x%" (
set target=!source:~0,-4!.%y%
"%VBOX_INSTALL_PATH%VBoxManage.exe" clonehd "%~dp0!source!" "%~dp0!target!" --format %y%
))