If you can send me your direct email address I have a working solution for this situation (Section Access Plus as I call it) - I can't post it here as it needs both a .qvw and an Excel sheet to control the permissions.
I'm looking to post it to the 'Share Qlikview's' shortly but that may be a few weeks away.
I know it has been a long time since you had this problem. But right now I am having a similar issue and I haven't found any answers so far. Could you please help me and tell me how you have solved your problem?