Are you talking about the Settings button on the Start menu? If so, the path is
Code:
HKEY_LOCAL_MACHINE\SOFTWARE\HTC\Manila\ProgramLauncher
You can place the settings in whichever slot you want, I believe it starts at 0 and goes across to the right and then down. The default position is 3.
As long as you put this in exactly it will then transfer you to the TF3D settings page.