I can't help, as I am a total n00b. But we are doing something similar.
I have asked a question regarding multilingual sites that includes as many of the resources available at the Dokuwiki Website as I have been able to find.
There are helpful articles here also in making the decision of whether to have 1.) three different installations altogether, 2.) three installations linked to one databank, or 3.) one installation with multitemplates and the data separated by your use of namespaces
en:titleA:titlea sp:titleA:titlea fr:titleA:titlea. It seems every one of those options is possible.
(Reference 1.) http://forum.dokuwiki.org/thread/253 , 2&3.) http://forum.dokuwiki.org/thread/70 .)
My own question is found at
http://forum.dokuwiki.org/post/1500 It contains specific links to some multilingual articles in the main dokuwiki website that you might find useful. I hope any discussion there may also prove useful.
Sorry can't be more help.
Tito Vergara