In this case, I'm looking for a language designed for exactly what Lua is targetted towards - embedding in a larger program. I already have an embedded language but, to be honest, it's pretty crap. In fact, it's distinctly weird, being designed by someone who was not a language designer, and who had no clue about how to design and implement an interpreter. Adding either floating point handling or the ability to define functions would take more time than embedding Lua would.
(It's better than nothing, and some users have done some impressive things with it.)