just bring gamemonkey or angelscript into your code, extending objects and exposing them to your script is just a matter of writing a simple proxy class (or calling some functions in angelscript). i’ve made some tests, gamemonkey is more faster than angelscript but its language is more like lua than c or c++… on the other side angelscript is faster to implement (for exposing c/c++ objects and functions to your script) but has a drawback of being slightly slower when running bytecode. anyway both are used in games for maintaining game logic and ai, and both are pretty fast imho. sure you can’t put a script function called in a inner loop of audio processing, but for scripting offline actions they work fine.
http://www.somedude.net/gamemonkey/
http://www.angelcode.com/angelscript/
take a look!
lou