Domain mapping and Cloudflare for SSL

Hi guys,

I have the following setup;
A multisite installed with a dedicated IP and am using a wildcard ssl for my subdomains. Now I want to extend by using domain mapping so that users can use their own domain names. Rather than installing another SSL on the domain name, I was hoping to route them through Cloudflare and make use of their SSL.

I have tried this with one of the sites but it returns a site not found even when I type in the subdomain name now. The mapping shows invalid each time too.

Could you either log in and see where I went wrong or else point me in the direction of some detailed idiotproof (yes I am in that category now) documentation?

Thanks so much!