WinHTTPRequest 5.1 -> SetClientCertificate issue

Hi there,

I've got a VBA script that I use to grab data from a secure server on the net. Everything worked fine until I had to renew the certificate.

The issue seems to be with the name of the certificate. Basically, I have two completely different certificates with the same subject name (let's call it "Billy Bob"). As far as I can tell, SetClientCertificate("Billy Bob") is now choosing the wrong certificate, and so authentication is failing.

I know it's not a certificate issue, because if I remove the other cert with the same name, it works. If I re-import it back in, it stops working.

Is there any way to specify a specific cert other than by subject name? This seems almost too obvious to be a bug in the COM object....

I searched the forum and found this thread discussing the same issue, but no response was made:
http://www.vbforums.com/showthread.php?t=565479

Anyway, any help would be appreciated. Thanks