[Typo3] real url, languages & domain records

[Simon Tuck]

Hi,
I'm trying to lock particular TLDs to languages, e.g.:
www.mydomain.de => german (default)
www.mydomain.com => english

I'm using realurl within a single page-tree (It would be easy if I used different page roots I suppose, but that has other 
disadvantages). I've set realurl to bypass the getvar 'L' (I don't need it if I'm using the domain to identify the language) 
and I'm using conditions in my TS:

[globalVar = GP:L = 1][globalString = HTTP_HOST=www.mydomain.com]
baseUrl = www.mydomain.com
language = en
locale_all = en_EN
sys_language_uid = 1
[global]

even though the host matches (according to phpinfo), the condition fails. I'm wondering if this is the best approach (i.e. 
would it be better / is it possible to control this via the real url configuration). Has anybody done this before? If so, 
can you give me a hint?
Cheers,
Simon