To get a partial accreditation cert, the person to whom you need to speak is the Dep CI UAS (UAS Staff Officer 1/2, as was) at HQ EFT, Cranditz.
Alternatively, speak to the CGI at 3 FTS/CFS Cranwell who will be able to point you in the right direction. You will also need to do Air Law and PPL R/T exams. If you are serving, the CGI can also help you here. If not, then try your local flying club.