The arduino does not under stand file types, at all, or at least in any thing like the way a PC does. Windows associates a file type with a program and then calls then calls that program to deal with the file. I can't think what application a .cvs file is for.
But I would try this,
Export the file from the application (and I mean export not save) as a text file. You can the see the format of data in the file with notepad.
After that its not to hard ( 
) to read the data from the file.
Mark