AC-3 import with AVC

I been trying to figure this out for a long time.

I usually edit videos that contains AVC video and 6 channel AC-3 audio.

I didn't mention container since I can easily change container without affecting quality.

I acknowledge that AC-3 audio is usually exported audio codec which is not meant to be edited with PP.

But please try to answer the question since I frequently edit this kind of videos.

QUESTION: How to import AC-3 (5.1)/6 channel audio with AVC video into Premier Pro.

If you need detailed info about the particular sample file then here it is - https://docs.google.com/file/d/0ByTDWZGFrJ-fdlZ6R2FPM3JPRmc/edit

Some said there is way to do it in PP CS3 with dll from Encore but I am using Premier Pro CS6, and I want to keep using it.

I don't want to convert/re-encode the file since that can damage the quality. (Unless you have suggest good converter that will maintain hi bitrates and channels of the mentioned sample file above. But still preferably not)

I don't want to demux the file since that will create conflicts in audio synchronization.

Please answer, I deal with this kind of videos frequently.

Thank You!