Yes, you can record just a audio track with microphone as you are listening to the audio playback. The problem is that if the playback is to close to the microphone, you will get a bleed effect, coupling the audio playback into the recording, causing a endless feedback loop that will cause more headache then it is worth. To solve that, get headphones for the playback.

In the support website (http://support.magix.net) under Tutorial (FAQ) there is a sextion for common questions, in there is a setup guid for sound recording using the sound card of your PC. Making sure you are only recording from Microphone would be vital. Sound PCs use a stereo mix, which would record any sound the computer makes.