Setting up apache as a proxy without subdomain

I want to run an Apache webserver that acts as a local proxy for
multiple
rails instances in the same domain. The domain seems to be a problem:
which
directives can I use for www.somehost.com/one and www.somehost.com/two
if
they are two different rails setups?
I came up with this but that does not work:

ServerAdmin [email protected]
ServerName somedomain.com:80
ProxyRequests Off
ProxyPreserveHost On
RewriteEngine On
RewriteRule ^/one/(.*) http://127.0.0.1:3000/$1
[P,L]
ProxyPassReverse / http://127.0.0.1:3000/

The wiki does not mention this case either.

Bart