Can you screw into car body filler?

[supersadie]

I am mending a hardwood window which was rotten in the corners. I finished it off by smashing it, having locked myself out of the house!

Having removed the rotten wood and applied hardener, there's only a thin shell of wood in the corners where I need to pin it back together. I'm planning on filling the cavities with car body filler (with which I've had good results in the past), but am unsure whether I can drill and screw into this once hard.

Would be grateful for advice.

Many thanks.