Multi-Site using Domain Module (D7) with Subfolders instead of Subdomains

Hello,

I need your help for a tricky use-case with the Domain Module:

I use D7 with Domain to create a site with multiple regional subsites (www.domain.com/germany, www.domain.com/austria, etc). A part of the content is shared, some other content is per-site and foreign content should not be seen nor be editable from another regional admin. Everything is multi-lingual, regional language and english. The domain module makes all this possible in a sleek way that almost made me wet my pants. There is just one problem:

I can define the domains using subdomains or actual domains:

de.domain.com/lang-code/path/to/content
at.domain.com/lang-code/path/to/content

but not as subfolders (no subdomain, instead first "subfolder" is the country code, second is the language code):

www.domain.com/at/lang-code/path/to/content
www.domain.com/de/lang-code/path/to/content

Does anybody know a way to configure this, or (if possible) do an apache rewrite rule to make it appear like this?

Any help is appreciated! Thanks,

Martin