WP MultiSite Network with different domains

Hi,

I want to make the following setup:
main site: domainname.com
sub site: domainname.eu/de
sub site: domainname.eu/africa
…

My approach was that all domains point to the main webspace.

Can you please help me:
1) is my approach technically correct eventhough the domains for the mainsite and the subsites are different?
2) if yes, what are the correct plugins to do so?

Thank you very much!!