The server's language is, indeed, established by the httpd.conf. I've checked my test server (Apache 2.2 on a Win7 box) and it shows that the languages the server will use has been split off the httpd.conf into
The languages file contains lines like:
# Language settings
IMHO, Vidahost is not providing you the service you're paying for so you may wish to consider the folks at WebHostingBuzz (in the UK?). I'm not sure whether they have or will configure multi-language shared servers but I'm sure that they will do so for VPS and dedicated servers. Use their ticket system to ask (or PM mattrussell - he's in the SitePoint boards frequently) to be sure.
AddLanguage sv .sv
LanguagePriority en ca cs da de el eo es et fr he hr it ja ko ltz nl nn no pl pt pt-BR ru sv tr zh-CN zh-TW