Given the bloated UN bureaucracy, your confusion is understandable.
According to that Human Rights Watch link I provided before, "Libya is set to chair the Libya looks certain to be elected chairman of the U.N. Commission on Human Rights." That's probably a different position from being the UN High Commissioner on Human Rights.
My point about Iraq is that it has systematically violated over a dozen UNSC resolutions requiring it to disarm. That sounds like a strange track record for hosting a conference on disarmament. It'd be like a bunch of hookers hosting a conference on abstinence.