Hi and welcome to GT !

I don't really know the software you have however one way would be to use a free music program like iTumes.

Load the MP3 into the iTunes library and then burn it to a CD as an wav file which you can then copy and import.

There may well be a more elegant way to do it (like open up the mp3 in your software and either export it as a wav file or bounce it to a wav file ore even use the save as or export functions.

best of luck !