Vista - Sending a digital certificate in a web service call?

Hi all, thanks in advance for reading this question.

I have an ASP (classic, VBScript) app that I need to modify to use a
web service call instead of direct SQL. I am in a restricted
environment and have no control over the source web server, network,
destination server, etc. The call will be kept inside the firewall.
The web service already exists on the database end.

The requirement is that I as the client present a digital certificate
as part of the web service request. This is something I've never done
before, and the main system programmer (Java) doesn't think it will be
possible using VBScript -- he stated it was difficult for him to
figure out how to do it in .Net as a simple test.

I was going to use the simple VBScript class available here:
http://www.codeproject.com/KB/asp/as...ebservice.aspx

But since the new wrinkle of using the certificate (I just found out
about that part a few minutes ago) I'm kind of stumped.

Is it possible to do this, and if so, how would I go about doing it?

Thanks again for the help!

Sincerely,
Dave Cantrell