NAnt - A .NET Build Tool

I tried to use attribute refid for <sources> tag, which
is sub-set of <link> task like this:

<fileset id="task.files.link" >
<include name="\Program Files\MyDomain\bin\libapp.lib" />
<include name="${Intermediate.dir}\command.obj" />
...
</fileset>

...

<link output="${destination.dir}/${App.Name}.dll"
options='${build.link.options}' >
<sources refid="task.files.link" />
</link>

The file set by refid is not recognized and there is no
action for <link>. If you include files directly under
the <sources>, the <link> will build my source codes.