wallet.dat ?
How did you lost your wallet? Can you describe what exactly has happened and than maybe there is some chance to find some solution.
I tried wallet.dat and it just says no items match your search.
I downloaded the wallet for PPCD to my desktop but I didn't notice there were no short cut links or icon tray symbols to pull it back up once you switch off the PC.
I had the wallet on the screen for my first 2000 PPCD transfer, so I turned off the PC and went away to work for 4 days.
During the 4 days I mined 60,000 PPCD in my hotel room.
I came back home and switched on my PC to see that the wallet had just gone with no retrieval options anywhere.
Which os do you use?
If it is win 7/8 you can search in C: drive / user / YOUR USER / AppData / Roaming / peercoindark
Before you can access that folder you need to enable view of hidden files.
But I think there is no need for that, just start PeercoinDark wallet again and all should be good, if you do not have wallet anymore just download it again and start, files from folder I mention before will be pulled automatic.