Reply to DJing only with internal soundcards?

Hi, first of all I'm no professional DJ. I just like to play music at my house or with friends. And before I spend $50 on a sound card I want to experiment something different and I believe it is possible.

Okay so I don't have a sound card, I have a PC and currently using Traktor 2 with Asio4all v2.

Now what I'm trying to do is being able to play music on Deck A from my rear PC audio jack to a speaker while listening to other decks with my headphones on the front audio jack. Yes I've heard this is possible, but I'm just going to figure it out myself.

Anyone know anything about this? It's simply has the same idea of external soundcards but only using internal soundcard.


Edit:

- So far I managed to set the Realtek manager to enable front and back audio jack, so I can hear same audio at the same time.
- Now, what I'm trying to do is be able to switch decks I want to listen to on my earphone.