Do you know of a runtime written in Java/J2ME, that is capable of reading and executing a script/binary file?
I wrote just such a language designed to be small enough for J2ME, and to not use reflection/code generation/etc...
It's open source under a liberal license, so you're welcome to take it, study it, include it in your own programs, or hack it to make it behave like you want.
For 'regular' Java, there are other languages that do more and are faster and more complete.