Duodecimal Sytems

I've done some reworking of the Silindion Number System, and I've decided to make
it a duodecimal system. Now, I know how to build this kind of system up, but at
the moment I'm stuck. I don't know how to figure out how to immediately make a
number such as (to take from another thread): 4009

Now I have the number 409:
minkeryon me millonteon ala '409'

which means:
2-60's on top of 2-144's + 1
(Note that some parts of the system contain a vestigial base-20 system).

Any help on this topic would be appreciated.


Thanks

Elliott