ya i can see some uses being valid and not that great of an issue. Im not really against the idea I just wanted him to know that others shared the same view.
It wouldnt be impossible to write your own interpreter that simply runs mIRC scripts. they are after all plain text files. But it would definately be an undertaking. mIRC has quite a bit of identifiers commands etc.. and you would have to implement all or none. (otherwise face the rath of posts such as "why doesnt blah work"). Plus you would have to keep it up to date in step with mIRC updates.
A workaround could be just as you suggested. call CreateProcess and specify SW_HIDE for the window visibility state and run mIRC as a background process. Then all you need is its window handle (obtainable) and SendMessage althou you will still have to parse a bit before sending to mIRC. It is doable just a large request.
It would be intersting to see someone do it.