How to fix that faux wood stuff they use on furniture now? It's like a high density foam?

Question:The very top of my china cabinet is damaged. Instead of using wood for the crown molding it's the type of styro foam stuff that lots of funiture companies are using. It's just one side of the piece- someone hand went through it when it was being moved- so it just this one chuck in the top. We got a great deal on this piece and I would like to repair the top. Any ideas? It's a big chunk missing so I can't fill it in with wood puddy because I need to somehow sculpt the design into it. Anyway to mold it off the one side?
Any ideas are great!!

Answers:
I don't know but I HATE it...