ServletContext in portlet

Hello,
I should start with: "I'm new with Vaadin...", but its obvious :*)

So, I have Vaadin portlet deployed on Life Ray portal. In server.xml (LF's Tomcat) is 1 variable and I have to load it in this portlet. This variable contains string with path to configuration file, so I need it in portlet's init() method.
In normal web application I could use simple "((WebApplicationContext)getContext()).getHttpSession().getServletContext()", but in portlet it's not possible (because context = PortletApplicationContext2).

Simplified question: how to load parameter from server.xml in Vaadin portlet?

PS: This parameter is set by 3rd person and I can't use other configuration file for it, e.g. web.xml.

Thanks in advance

Ehm.. sorry for that dumb question :D I shouldn't ask on Friday when brain is already in "sleep mode". Solution was so simple, I just had to wait till Monday:

InitialContext ctx = new InitialContext();
ctx.lookup("java:/comp/env/foo-bar");