How to Create Client Certificate

I'm working on a C++ app using WinHTTP to communicate with a web
server. Basically I'm trying to do what's document here:

http://www.windowsecurity.com/articles/Client-Certificate-Au thentication-IIS6.html

I'm using Virtual PC/2003 Server as my CA.

I can't get the Client Certificate working. I do get
ERROR_WINHTTP_CLIENT_AUTH_CERT_NEEDED, I do enumerate my Local Machine
store for the right certificate and call WinHttpSetOption(). When I
try again I get 403 Access Denied. The specific problem appears to be
address mismatch because the Client Authentication Certificate was
exported from the machine that actually requested it. Ultimately what
I want is one certificate I can automatically drop on 100 different
machines so they can all authenticate with 1 web server. I assume this
is do-able. Can someone explain how? Thanks.

My 9-year old son says hi.

Thanks in advance,.