But the whole point is that there is a script installed in the mIRC which does it.

Like I have a funciton in that script which is called hello

so when someone click on the link then it runs the Hello function in the script. If he doesn't have the script installed, then IE will show a broken link (Like in ekonkey, if you install it, then writting something like [url=e2k://hash][url=e2k://hash][url=e2k://hash]e2k://hash[/url][/url][/url] will put the link in the edonkey program).

It is not like I'm want to control a computer, I can only do the commands that IE sends only if the script is installed!!!