Delegate unlocking accounts on server 2003

I need to delegate unlocking a specific account which I have allocated to it's own group. I've created a group containing the users that will have this ability.

I think I need to create a custom task when actually creating the delegation but I can't seem to find the correct object to include. Server 2000 instructions mention lockouttime which I cannot find on the server 2003 AD delegation window.

Thanks.