Importing entities from other custom stories?

[GettingTheBasics]

So, I've been set a challenge (by a friend) to make a CS with lots of jokes and stuff. I am really new to this and have only had a couple of weeks of experience.

I was wondering if I was able to import stuff from other CS's like Late Night Drink because I find it really tricky to make my own (I have made my own item before that looks like the grunt but when you pick it up, it turns into fresh meat).

So I tried to import a spinning painting from Late Night Drink. I copied all the files (well, only the ent file as the model was already in the game) and tried to use it in the level editor. I was able to place down a painting that didn't spin (but it still used the ent file that I copied over) and when I played the CS, there was no such painting.

Am I doing something impossible, wrong or stupidly easy?