VBA code to do SOAP Client Certificates

We tested successfuly with SOAP-UI to webservices to confirm we could load the client certificate. Thanks, it works. Now we want to get some VBA code to make the connection which will do the same thing. Essentially we are extending EXCEL with VBA to transfer data into web services. We can already do this with http, but not https where client certificates are required (regular 1 way https works fine). Any suggestions to duplicate the functionality of the SOAP UI in a program that would do this?