Not sure it is the easiest way but I use Audacity to create .wav (MS format) that can be imported in the the Jam Manager. In BB I use the create wav tool to create either a wav or mp3 recording. The BB wav file, I think, is a raw sample format that is not the same as the MS .wav format so Jam Manager doesn't recoginize the file. I then start Audacity and load the BB wav or mp3. In Audacity I use "export" and save as .wav (MS).
Robert