Cocoon 3.0-alpha sitemap properties

I created a block for C3.0 and tried to use properties defined in a
*.properties file. The logs show that the file has been found and I
can see that properties are found loaded,

for example:


 935 2012-11-03 20:53:12,369 btpool0-1 DEBUG
impl.SettingsBeanFactoryPostProcessor - Property:
base.path=/home/mansour/docs/documenation
 936 2012-11-03 20:53:12,369 btpool0-1 DEBUG
impl.SettingsBeanFactoryPostProcessor - Property: sun.cpu.isalist=
 937 2012-11-03 20:53:12,369 btpool0-1 DEBUG
impl.SettingsBeanFactoryPostProcessor - ===== Settings End =====
 938 2012-11-03 20:53:12,369 btpool0-1 DEBUG
support.DefaultListableBeanFactory - Finished creating instance of
bean 'org.apache.cocoon.configuration.Settings'

However, doing this in my sitemap.xmap:

  <map:match pattern="doc/{1}">
          <map:read src="${base.path}/welcome.html" />
      </map:match>
    </map:pipeline>

Does not work, and it reports that file is not found.

Any idea or documentation for this ??