[TYPO3] RealURL & country domains

[Sebastian Fuchs]

Hello list,
if have a conceptual problem with RealURL.

I set up a multilingual side, using typo 3.8.1 and realurl 1.0.0 with 
two subdomains:

de.sidename.com (german side)
en.sidename.com (english side)

everything works fine so far.
now the customer would like to get rid of the subdomains. instead he 
would like to have the domains availaible under:

sidename.com/de (german side)
sidename.com/en (english side)

at the end it should be possible to reach:

sidename.com/de/ (german side, default language)
sidename.com/de/en (german side, english language)


does anybody know if this is possible at all?
I tried a lot of configurations through vhosts, .htaccess, 
localconf.php, domain records but I haven't found any examples in this 
direction.

thanks a lot,
regards,
sebastian