Reirect Multisite to multi domains

Multisite domain mapping is mapping a domain (http://www.domain.fr) so it shows the content of a subsite (http://www.domain.co.uk/fr/)

It consists of these parts:

1) Edit the dns for domain.fr to match what you have on domain.co.uk

2) Park/addon the domain so domain.fr loads domain.co.uk (it may initially load “There’s no site by this name” and that’s okay)

3) Using the plugin, tell WP that when someone’s looking for domain.fr they want domain.co.uk/fr/’s content