com.intellij.lang.LanguageDialect with idea 7.0

In what extent does intellij7 support language dialects?
See there is no screen where language dialects can be associated to files (like in 8.0). Is there any way to do this programmatically?

Tell IDEA that your PsiFile has language LanguageDialect parameterized
with your base language.

Note, that in Demetra every language can have base language and
therefore be a dialect, so there's no need to use LanguageDialect at all.

Thanks Peter, makes sense.
Nevertheless, I will need to provide slightly different highlighting for each dialect. But I think I could hook into the Language.getSyntaxHighlighter(...) for achieving this.
Cheers, Dan