Removing curtain tieback hook screw

chezybezy

Me again I'm so sorry for all these but I just don't know who else to ask.
How do I remove the screw bit from a tieback curtain hook that's left in the wall after removing the actual hook? It's just a fat headless (on purpose) screw thingy? Pliers don't seem to shift it either. I'm having a bad day, I can't even drill into the wall to put a picture up (seriously it wont go past the plaster), but that's another post and I dare not do another today!

This is what I'm left with after the hook part twists / unscrews:
http://imgur.com/2xxw039

Warwick_Hunt

Vise/mole grips.

EssexExile

If you've got a box of odd nuts you dig out two that will fit on that thread. Screw them both on then tighten them so they lock together, then undo using the nut furthest on. Or vice/mole grips.