Issue: converting mediawiki local templates {{:Help:Header}}

In media wiki you can either use templates from the template NS, or you can create "local templates"

This is also based on my question in the question forum about having more then 1 forum act as template, or have template functionality.
I used to work with a lot of "Includes" on my pages.. browsebars, headerbar etc.
These were normally created in the local namespace.

for example:
http://www.birthright.net/forums/sho...le=Help:Header
was included in pages like:
http://www.birthright.net/forums/sho...=Help:Template

the mediawiki code for local templates is by adding a : sign for the template include, telling mediawiki to search for the template in the current namespace. ie : {{:Help:Header}}
during the conversion this way of writing templates are converted, but the pages are not moved.. thus the pages are "broken"
most of them went well since both were in the template NS (documentation pages of templates), but others like help pages are not

perhaps its a good idea to have an extra BB-code functionality [include]PAGENAME[/include]