Windows 8.1 GPO's on Windows Server 2008 R2

I have a Windows Server 2008 R2 standard as the domain controller.

and we have added several windows 8.1 computers to the domain.

there are several settings, like lock screen image, that we want to set for all the windows 8.1 computers, but that setting is not available on Windows Server 2008 R2's Group Policy Manager.

is there some way I can add those to it?

(Group Policy Management v 6.0.0.1 & Management Console v 6.1 --- in case it helps)

thanks