[Galadriel E'lyn]

I've been through the whole chapter two, actually completed every quest needed to go to Luskan, but I've been intrigated by that pillar in the Charwood haunted forest, the pillar of Gur-Atol. I haven't found anywhere some information about what runes I must press in order to activate something else that 'Skeleton warrior spwaning'. Anyone can give me a clue on what sentence I have to create with the runes in order to do something else?

Thanks!