Just forget it. If you learn a bit about the Web, you will see it makes no sense.
Your client Web browser is executed on a number of different platforms, so
is not available in general case, as CLR is also not available. Just think a bit about it. And if this is ASP.NET on Windows, it does not change anything. You are not going to show a form on the server side, are you?
(And do yourself a big favor, don't even consider ActiveX. Not all browsers support it, not on all platforms. But more importantly, this is not a legitimate thing for a Web application, because this is utterly unsafe. The experienced users won't even think about using your side as soon as they see that you are using ActiveX.)