Domain name only instead of prefix

Hi, I'm trying to build a multilingual website in Drupal 5.7.

I have tried Localizer first but the menu translation sucks. i18n works better for me, but I'm missing an essential feature that Localizer and i18n in Drupal 6.2 both have but I can't find it in 5.7
I need the language to be domain based instead of the default prefix.

For example:

I have a English, German and Dutch website. Instead of:
www.domain.tld/en
www.domain.tld/de
www.domain.tld/nl

I need the language to be based on:
en.domain.tld
de.domain.tld
nl.domain.tld

I think it's an feature that is used a lot, and I can't believe that i'm the only person who needs this feature.
Are there any plans for this feature in Drupal 5.7? Is it available but am I looking on the wrong places.

Thank you.

With kind regards,
Eric