Hi Matini,
If no-one has said it yet, welcome!

Your best bet is to not use the domain.local at all,
Just configure your domain.nl, create your DNS record to point at your public IP and you are done.
The trend towards setting up a seperate .local domain for your internal network is a windows thing... You don't need to do it here.
With regards to your 'test' ibay If you wanted the contents to appear in domain.local/test AND domain.nl/test then you should put it in primary/test instead of it's own ibay.
As Ray said, the server won't resolve <ibay-pointing-at-primary>/<other-ibay>
but it will resolve <ibay-pointing-at-primary>/<directory-in-primary>
Hope that made sense!
