It seems that you are over-thinking this. What is your ultimate goal with the file naming?
If your goal is unique names by the camera so that there are no naming collisions on your hard drive, you cannot depend on the camera doing this for you. In this case, you are best using a third-party downloader that will rename the files as you desire as they are transfered off the card, then reset the counter back to 1 and reformat the card.
As an example, I use Downloader Pro by BreezeSys.com. Using the exif data, I have it rename the files from dsc_nnnn.xxx to yyyymmdd_nnnn.xxx based on the date of capture.
---------+---------+---------+---------+ Joseph K Seattle, WA, USA