multisite transposh create subsite for translated content

Hi, i have a multisite install and am working with the transposh plugin for translations.
If i add a language i can visit that by going to domain.com/NL where NL is the country.
I would love to be able to not redirect to domain.com/nl but to an other domain for that specific language.

I understand that i can use a iframe but thats bad for seo as its not indexed

Is there a way where i can create a new subite and include the content from domain.com/nl or an other nice way with rewrite rules or smth which is also not to complicated to maintain?

The transposh developer is not really helpfull