Quick question for you.
can you just track the object in combustion and then apply those transforms to your emmiter??? if not I think there is a script that allows you to bring maya animation into Combustion.....never used it so i dont know if it will help you or what...the web addy for that script is: www.fido.se/mtoc/index.html but like i said I dont know if this script will help for what you need.....
I know the newest version of FFI can import FXB files. Not sure if they added this ablility to combustion 2.1(I dont have it in front of me to check). If so then use this plugin:http://www.kaydara.com/support/download/index.phpand export the locators from maya.