EBS Security - Restricting the Responsibilities that a Responsibility can provision?

Hi,

We are using EBS 12.1.3 with HR and various Finance modules (PA, PO, GL etc) enabled.

I'm trying to establish if its possible to customise the System Administrator responsibility to only allow the provision of a a set list of responsibilities.

For Example..

'HR System Administrator'  can only provision (user defined) HR type responsibilities

and likewise 'Finance System Administrator' can only provision (user defined) Finance type responsibilities

Has anyone tried anything similar? or know if it is technically possible?

Thanks

Tony