If you're okay with escaping from the clutches of mIRC script, there are also dlls like
ruby4mirc,
tcl4mirc,
python4mirc,
perl4mirc and more. All of these language bindings have XML libs associated with them which you can use instead of mIRC. I would go this route if you really have complex X(HT)ML to parse. Using an external program like a C# exe is okay, but the integration is lacking-- the above dlls can all be embedded *within* your mIRC script, so it's much easier to use and modify. Also, all of the above are dynamically typed languages, and, typically, dynamically typed languages are easier to write quick prototypes with, so you'd probably get off the ground a little faster than with C#/C++/Java (unless of course you're an expert in one of those languages).
