How can I get the windows AutoLogon password?

I have a computer with configured Auto-Logon.
After a restart of Windows it automatically performs a login with a predefined user.

I would also like to connect via Remote Desktop to this computer. But therefore I need the password for this specific user.

I already know that the AutoLogon can be configured in the registry:
Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
AutoAdminLogon(REG_SZ) = 1
DefaultDomainName(REG_SZ) = MyDomain (or empty)
DefaultUserName(REG_SZ) = MyUser
DefaultPassword(REG_SZ) = MyPass
But in my case there is NO entry of DefaultPassword. Despite this missing password the AutoLogon still works. And the password is NOT a empty string.

How can I retrieve the password?