I have it too but I've never been to Movarth's Lair. I don't think that's where you got that staff. I have the big Prima game guide. It doesn't have Grand Staff of Charming listed anywhere in the index and it doesn't mention that staff anywhere on the pages about Movarth's Lair. I've been searching this book for over an hour and I can't find where that staff comes from or who it's supposed to go to.
If Mortavhs lair is that really far north ice cave, the staff is part of the quest chain to get Ommund's friendship in the College of Winterhold. --- Official Dark Lord of PotD http://i216.photobucket.com/albums/cc137/Lordgrievous/t5q1dd.png
I took the staff to him but there are no options to talk about it. In the quest menu it's still unmarked that I found the staff. It says I need to search Shriekwind Bastion for it. I went back there and I've been through every room at least 3 times. I can't find another staff. It looks like this is a glitch. I guess I have to keep the staff. I think I found it before he asked me to get it.