Why wouldn't you imagine that? You're allowed to install "exe"s on any unix dedicated host even without root access, except theyre binaries.. or sometimes they're just shell scripts with just as much power. I'm sure Windows servers have the same kind of privileged user protection that would keep your non-admin account from doing damage to anything you shouldn't.
The host would obviously have to give you the permissions to install exes, and you'd also need some kind of remote login/vnc interface so you could login to the UI and run mIRC. Most hosts that offer this kind of stuff are pretty pricey, but they exist all over the place... of course, it's way cheaper and easier to just convert your script to Tcl. I doubt it's as hard as you make it sound. If you can write mIRC script, you can write Tcl.
