Sending data to https using a certificate

I am making an app that will send data to an
ASP page using a certificate.

I tried with the internet transfer control like this:

Code:

---

Inet1.Execute "https://server/page.asp", "POST", doc.Text

---

The return was that I need to have a certificate
to authorize the client.
I HAVE the certificate installed, of course.

When I connected to the same page using MS
Internet Explorer, it showed a list of certificates,
I chose the certificate and everything was OK.

So, what am I doing wrong, how can I connect
from my app?
Please answer ASAP as I need to resolve this in two
days.

Thanks!