I am using the Sony Digital Voice Editor 3, but it won't give me the option to record an MP3 file. Do I have to purchase another program?
There is no need to purchase another program. Download and install the application and then you will be able to convert the IC (recorder files) into MP3 file format. This is a standard feature provided by this application. You might need to transfer the .ic files to your computer before doing the conversion. Alternatively, update the application to benefit from this feature because it's possible that you're using an outdated version of the software which lacks this feature.