I've had this problem as well regarding Boo syntax highlighting and had to resort to writing my own syntax highlighting.
For a reference, you can find it at https://github.com/Shammah/boo-sublime.
Now your script syntax looks doable with a few regexes.
To start, I'd recommend reading the guides at
Basically, you create your regexes in JSON format and convert it to the format supported by Sublime Text.
Sublime's system is based on TextMate's system, which you can find a reference at http://manual.macromates.com/en/language_grammars
It might be a bit tedious at first, but once you get it working it's all worth it in my opinion.
I wish you best of luck!
PS: If you ever get it working, you might contribute your syntax file / package to the Package Control library, so everybody else who might need such plugin can enjoy it as well .