Wheel lock at XC60 defective – How to open?

Hello all, with my XC60 this wreath of a rim lock (Original Volvo) is “doll” turned and does not open any more. About the search function I found no suitable thread here, so I open a new post. Long speech, crooked sense. I (and the workshop) do not get the wheel screw open any more. The workshop wants to weld now something on the screw, but this would make the rim very probably “black” by the heat. My idea would be to stick the adapter for the wheel screw with Loctite and try it like this… Do you think that could work? Or does anyone here have a different idea?