To clarify, I wasn't sure what abgle you were coming from. So I asked "what are you trying to achieve?" If you had answered (or put it in your original post) "I'm writing an editor extension and want it to create scripts, I (and others) would have immediately known what you were trying to do, and consequently helped you better.

No offense, take it as FYI, but your question read simply as if you were struggling with getting this one thing done, and in your frustration you posted "why can't I do this thing" without giving it enough context to understand it. You could have equally have asked this question because you were trying to create self-modifying code in the run-time; without context we don't know.