Welcome to the forum.
Unfortunately, you have posted to the Tips & Tricks sub-forum, which is a repository for articles on how to do things in the program. Not many people read here. Maybe our trusty MOD, Steve Grisetti, will move this out to the main forum, where you will receive more replies.
If I understand correctly, you want your recorded Audio to continue, regardless of what the visual is, but where you have the Video from that shot, want the Audio to sync up. Is that correct? Basically, you are looking to do a variation on L-cuts (outlined in this ARTICLE), but just wish to maintain Audio complete, and replace segments of the Video with either other Video, or with stills, or Titles.
There is one consideration, and that is if you wish to use other Video, that has its own Audio muxed (Multiplexed into one file with both Audio & Video). PrE's big-brother allows one to Lock a track, but PrE does not. When one drags a muxed Clip to the Timeline, it will want to replace both the Audio and the Video. Probably the easiest workflow is to Rt-click on the long Clip and choose Unlink (can also be done by Alt-clicking on just the Video). Then use the Razor/Scissors, or Ctrl-K keyboard shortcut, to Cut the Clip where you wish to replace the Video. With the Audio & Video Unlinked, Rt-click on the Clip and choose Delete Video. This will leave the Audio intact. Do not worry about the Cut-line in the Audio. Now, with the replacement Clips, drag those to Video 2, and its Audio should go to Audio 2. Trim and position this replacement Clip, as is necessary. Rt-click on it, and choose Delete Audio to get rid of its Audio stream.
Hope that this helps,
Thanks for the info.
I'll get back to you if I need more help.
You are most welcome. I hope that it helps.