This does not seem possible (thankfully!). Have you considered using JsFiddle? It may be useful for your purposes:
http://andrewwooldridge.com/blog/2011/03/16/stunning-examples-of-using-jsfiddle/
I suppose you can't embed JsFiddle here either, can you?
If it's worth saying, but not worth its own post, even in Discussion, it goes here.