How to change Machine name without Prompt for credentials

Hi

I'm hoping there's a way to do this, but I'm not sure.

I have an OU configured which contains some Computer accounts and a couple
of user accounts. To one of the accounts I've delegated permissions to add
and delete "computer" objects in that OU.

When I'm logged into one of the computers in the OU and I try to rename the
Computer, I'm prompted for credentials, even though I'm already logged on
using the delegated account. I enter the username/password and all is good
but I'd like not to be required to enter the user/pass. Is there a way of
doing this or some settings that I need to enable in group policy for it to
work as I would like?

TIA
KIWI