Try this:
public static Regex regex = new Regex(
"^Chapter\\s+(\\d+)\\:\\s([^\\n]+)",
RegexOptions.Multiline
| RegexOptions.Singleline
| RegexOptions.CultureInvariant
| RegexOptions.Compiled
);
No guarantees, but it seems to work when I run it through Expresso.
BTW: If you want to play with regerexs, then get a copy of
Expresso [
^] - it's free, and it examines and generates Regular expressions. I use it a lot!