Here they want you to talk about your past admin experience if you have any, and to show your enthusiasm for this side of things! Fake it if you have to. Pretending that you are desperate to become the new admissions officer will help you to get the job if that's what they are looking for. If you have experience of running your own courses, managing an entire programme, or doing a specific administrative task then mention that. If you can, give an example of a contribution or innovation that you instituted in that role. If you are at the very start of your career then simply show even more enthusiasm and emphasise the transferable skills that are vital in these roles, i.e. being efficient, well-organised and a good communicator.