OK, here (on inn-patches list) are the patches to extend the number of
"standard" headers the filter_innd.pl/py can be used with.
One is against 2.4.4, and other one against a CURRENT of 20080523. 
The difference is mostly just fakeinnd.c in CURRENT, which does not exist in
STABLE.

I've tested the 2.4.4 version and it seems to work nicely as expected.

-- 
Opinions above are GNU-copylefted.