If you add the branding image place holder yourself, you assign it the id. But if there's only one, SetBrandingImage will use it and there's no need to specify it explicitly.
well if you really want to do it the hard way then...
you can create a plugin which moves the image in that way (the id of the control can be found using something like winspy++) and then you call the function in your plugin in the script
or
you use the system plugin and say use SetWindowPos() and alter things that way
or
just use resource hacker which is far easier to do on the ui.exe