Where do I find include files in doxygen generated namespaced functions

Where do I find include files in doxygen generated namespaced functions

I'm using doxygen to document my c++ code. I have problems with the
documentation of functions with namespaces, i.e. in the following header
file http://fimex.met.no/doc/GribUtils_8h_source.html or in short:
/// function with prefix, without namespace
void mifi_grib_check(int error);
namespace MetNoFimex
{
/// function with namespace
std::string gribSeconds2stepUnits(unsigned long seconds);
}
The mifi_grib_check() function can be found in the documentation under
Files->FileMembers, with reference to the header-file needed to include
the function: http://fimex.met.no/doc/globals.html
The gribSeconds2stepUnits() can be found in the documentation under
Namespaces->NamespaceMember: http://fimex.met.no/doc/namespacemembers.html
My problem is now: Which header-file do I need to include when I want to
use the gribSeconds2stepUnits() function. I didn't find any connection,
and unless I use an IDE or another tool to find the correct header, I'm
often lost.
Is it possible to add the namespaced-functions to the Files->FileMembers
list? In my opinion, a namespace is nothing else than a prefix like the
mifi_.
Best regards,
Heiko