Hi Ian,
I'm a Work-based Learning Advisor from City University London and often place students in IT Helpdesk/User Support roles in schools etc, in fact most of our IT students looking for placements will do this kind of work as it provides them with a really good technical grounding - something they will need when they graduate and search for graduate roles. At City, we use SFIAplus to map our students' learning, it might be of use to you have a look at this if it's not something you've come across before? You can see the basic version here SFIA Foundation | SFIA Home | SFIA Foundation and if you are a member of the BCS you can see the full SFIAplus version via the main membership page. It's an industry standard matrix of all the jobs across the IT industry that people can do - at various different levels. Most students will start out at level 2 and work their way up. Helpdesk/user support comes under USUP - Service Desk and Incident Management.
Hope this is useful.