Wow, I've been looking for something like this to be integrated into my game engine.
At the moment I'm using the Thorium scripting language (german link) for this task.

Just took a quick look at it, but it failed to compile on Mac OS X 10.6.3 (Intel) with FreePascal 2.4.0 (just wanted to test if it would work with 2.4.0, I will use a more recent FPC version tomorrow) with some errors about wrong parameters for FormatDateTime and StrToDateTime.

Well, as I said I will take a more thorough look at BESEN tomorrow.