The Microsoft DV codec is a codec for the DirectShow media system. Combustion only supports the Video-for-Windows and QuickTime media systems. DirectShow is the replacement for Video-for-Windows.
You will need to render to another format and then convert to your DV codec in another program. QuickTime has a DV codec. Or you can install a third party Video-for-Windows DV codec like the one from MainConcept.com or the DVSoft codec from Adaptec.
I'm not sure about the miroDV2 codec.