Ooops, my bad, it's really working. Actually I read the whole thread but what made me wrong is I didn't try it, I just read it.
I try to change the Id next to "quote" with the message Id of the locked topic and I'm surprised that the whole contents of the locked topic appeared. I thought that the "copy the contents" you're talking about is copy the locked thread like this...

This what makes me a little bit confused because I misunderstood it.

Well, it's really working. Nice tutorial mdayonliner. They might say that something like this topic has been discussed before but I'm still grateful that you've posted it here because if you didn't,  I won't found out a useful trick like this