You will need to be working with a recovery program that specifically says it can work with Dynamic Disks. Don't jump the gun until you have exhausted all your possibilities.
I'm not sure about RECUVA, but I know that Acronis True Image Home comes with a Plus Pack that has that functionality. You could download and install both programs on a trial basis on another computer, then burn a bootable disk that you can use on the problem computer without an operating system.
But if you are willing to lose it all, then yes, you need to convert to a basic disk, then format and start over from scratch.