regedit stores its last-key-position at
        HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Applets\Regedit\LastKey
This is what it uses to know where to start up at.



There are several utilities to make an already-running regedit.exe jump to a specific key:
    http://technet.microsoft.com/en-us/sysinternals/bb963880.aspx   (SysInternal's RegJump)
    http://www.codeproject.com/KB/applications/RegEditGo.aspx