c# console app - find file by guid and rename to CSV value

I have a directory of GUID file names like 4a29df4d-e7c4-4802-9f7b-f7f46d8dba72 with no extension. we have a csv file with the real name and extension. we need a console app that will lookup the guid from the file system to the csv file and then rename the file its correct name and extension. you can assume all of the files are in the dir of your exe, you can also assume that the mapping csv will be called [login to view URL] and will be in the same dir as the files and the exe. this way i can just run the exe and nothing else is needed