If someone of you are interested, here you can find a native plugin for Navision 3.60 for Talend.(using C/FRONT)
With this one you can extract data and transform it easily with talend, and load it anywhere.
You can maybe load data into Navision but I never test it.
It's only working in Navision to 4.x version not higher version.
I ask to talend to adapt this component but for the moment I have no response.
http://www.talendforge.org/bugs/view.php?id=2460
Tell me if you are interested to have it working with Nav 5.x or 6.x.
You can find talend here
http://www.talend.com
and the list of the components here
http://www.talendforge.org/components/index.php
you can find the plugin here
for Talend before v3.0 you nedd this one
http://public.groupetwc.info/talend/3.0%20et%20Inf.rar
and other you need this one
http://public.groupetwc.info/talend/3.1%20et%20Sup.rar
and you need to specify a folder for navision driver you can find files here
Nav3.70A
http://public.groupetwc.info/talend/3.70A.rar
Nav 4.0
http://public.groupetwc.info/talend/4.0.rar
Nav5.0
http://public.groupetwc.info/talend/5.0.rar
Nav2009
http://public.groupetwc.info/talend/2009.rar
Full Pack here
http://public.groupetwc.info/talend/Talend%20Nav.rar