It's Ca-pou.
There's no accent on the 'e' like Eboué.
A very short 'oo' sound as opposed to 'ooo', kind of like a gorilla sound as opposed to an amazed sound at a magic trick.
This.
Although Jamie Redknapp and Hoddle insist on calling him 'Capooey'
By far the best example I've heard (although a gorilla amazed at a magic trick would be interesting to hear)kind of like a gorilla sound as opposed to an amazed sound at a magic trick.