Forcetype for virtual domain

[Anon]

I have used the forcetype directive quite a bit to make my dynamic sites searchable, but I just ran into a snag. I now have a virtual domain that runs on the same apache as my main, but runs from a sub-directory (did that make sense?) So I have:
www.maindomain.com
and
www.virtdomain.com
where virtdomain.com runs from
maindomain.com/virtdomain

Ok so now I want to have
virtdomain.com/somescript

be forced to be PHP so that
virtdomain.com/somescript/stuff
can generate my dynamic pages.

Any thoughts?

[Anon]

What do you mean "forced to be PHP"??

[Anon]

Using the Forcetype directive you can make a request for say:
http://www.domain.com/scriptname/somevalue/otherval

Not request a document at that location, but actually run a script using somevalue and otherval as variable values.
See http://www.audiblefaith.com/pages/sg000292 for an example.
pages is a script not a directory, and sg000292 is a song number. If sg000292 is replaced with cd000058 it is then a CD page instead of a song page.

Read Tim's column on building dynamic sites with search engines in mind for more info.

Anyway I need to know how to do the same with a virtual domain. It works for virtual domains that point to the same webroot, but it does not work for virtual domains pointing to subdirectories.