ddoc file on command line

[Yao G.]

According to the DDOC spec (http://digitalmars.com/d/2.0/ddoc.html) if you  
want to redefine some macros, one way is to pass one file with the .ddoc  
extension to the command line, but it doesn't work in my setup. For  
example, suppose I have the file yao.date.calendar, and I want to generate  
the documentation, so I compile with:

% dmd.exe calendar.d docbook.ddoc -Dfcalendar.xml

And it doesn't work. Am I doing something wrong? Note that the file is  
generated correctly but the few macros that I redefine (DDOC,  
DDOC_SUMMARY, etc.) don't get replaced with the new ones. The docbook.ddoc  
is on the same directory where I have the *.d files (code).

Thanks in advance.

-- 
Yao G.