I may not have understood what your problem is until (maybe? now: you want to style the link to a page which isn’t actually current but the ‘parent page’ of the others as ‘current’.
I’ve found links to these forum posts that may help you:
But I haven’t tried these solutions yet. If not helpful I’d suggest to call in the help of @Waldo or @cyberdave ?
now: you want to style the link to a page which isn’t actually current but the ‘parent page’ of the others as ‘current’.