Arcane Lock is only passable by the caster. Stronghold builder's guide has an Improved Arcane Lock, which is a third circle spell, to which additional people can be added at a cost of 5 gp each (205gp +5gp for each additional person besides the caster). Is this the spell you were thinking of?
Are you missing any of the books, by the way? When I do my upload to my website, I'll toss in anything you're missing if you give me a list.
Then I'll probably go back through and delete all references to this activity in the threads. LOL.