Without more information one can only comment quite generally. The usual method is that people create the podcast in a program or online service, producing a feed which they then submit to Feedburner. From this, Feedburner creates its own version of the feed, adding some extra tags, and this is then submitted to the iTunes Store. As far as the Store is concerned the Feedburner feed is the podcast feed.
You can change the feed from which Feedburner works in Feedburner, but I can't advise on specifics - you would need to look in Feedburner's Help for that. Doing this doesn't affect the Feedburner feed as far as the Store is concerned.
If you want to move the Store to using a different Feedburner feed you need to follow the proces described here:
You do not need to do this if you are only changing the feed Feedburner works from.