Document Classes ⇒ [beamer] Set title and author position

[deus]

I'm trying to make a Latex beamer presentation, with a custom background. Traditionally, the author, title, institute etc on the title page are automatically placed on the page, but I would like to give them a different location. Is there a way to specify the coordinates of those items, or would it be possible to shift the title a certain amount of space upwards?