Retrieve url path (host name plus path)

Hi all, 

As I currently work on google's sitemap generation, I have to know the
host name and path of the request. 

I have a look into inputs modules but I only see one that gave information
about "lenya document" (required to have an uuid). 

In my use case, I don't have a lenya doc... Here comes the design main
lines : 

- url finish with sitemap.xml (for example http://example.com/sitemap.xml
, http://www.example.com/toto/foo/sitemap.xml)

- publication's sitemap.XMAP intercept sitemap.xml ending and mount a
sitemap.xmap in seo module

- in seo module, I have
-- a match on sitemap.xml
-- a navigation module generator
-- a navigationToSitemap transformer

- into this transformer I have to know the entire url for generate a good
sitemap.xml, I think to do this throw a <parameter name="baseUrl"
value="{anInputModule:key}">

The base url retrive have to be "proxyied", have to be the same as the
client see... 

Any help would be great appreciated, 

Have a good day
++