Sending response headers with eRuby

I have a little Ruby program that runs over HTTP via eRuby. I need to
be able to send custom HTTP status codes (and other headers) but it
seems that they’re all set and flushed by the time my rhtml file is
processed.

I see this is possible by running a straight Ruby script with the CGI
library, but I’m not able to call scripts in /usr/bin (where Ruby is
stored) over the web on my shared host.

Is there any way to send headers with eRuby?

Thanks in advance,

Alex