switching GS' basic-language - domainnames and searchengines

[Belletage]

hi,

I have a dname.com, dname.de and a dname.nl,
basic language ist german, main domainname is the
dname.com, on which dname.de becomes attracted by the htaccess.

The dutch-sites comes with/by dname.com/nl,
the german site with dname.com and

Code:

<link rel="alternate" hreflang="nl" href="http://dname.com/nl/" />

Now: what can I do with the dname.nl?

Its possible and advisable to try to get somehow
from dname.com/nl a dname.nl in the addressrow of the browser?

I think, its about switching (messing around) GS' basic-language?

thanx for tips,
best B.