Does WebMatrix support authenticated custom NuGet feeds?

So I have added a custom feed, https://dev.fpweb.net/httpAuth/app/nuget/v1/FeedService.svc/.  This feed requires authentication.  

WebMatrix simply gives me a 404.  Visual Studio prompts for auth.  I have tried embedding my creds in the url, like so https://josh:passwerd@dev.fpweb.net/httpAuth/app/nuget/v1/FeedService.svc/, but to no avail.

Thanks,

Josh