Hi I came across your problem while browsing. The solution you need may already be partly in place at your school. Bristol has a licence for the Perspective product CLM which is used for tracking attandance and progress of learners attending lessons/courses offsite. By using SIF linked to the schools' MIS and with CLM as the co-ordinating hub, attendance marks can be shared/updated irrespective of which MIS the schools are using. As SIF is also in course of being implemented in Bristol your solution could well be at hand. If you need more detail or who to contact please let me know.
