There is an equivalent to the Multi Controller button on my old 1Ds Mark lll.
With it, I could move around the focus point, while looking thro the viewfinder.\
In Live View mode, I could also move around the focus point and then zoom in to focus manually.
On my 5D, I have the second of the above two working - i.e. manually focusing in live view mode.
But, I can't work out how to dedicate the Multi Controller button (it's the one below the Start/Stop button) to moving around the focus point, while looking thro' the viewfinder.
How can I set it to do this?