Hi Dave,
Yes I tried, I finally got it working by installing old drivers from some other source. This was the ALC3220 audio codec drivers from Realtek themselves. And I got the required option, some images about the driver details and the option I was searching for:
But before I could properly check if everything is working well, yet again windows installed newer drivers. I contacted someone else using an HP laptop and they have this option by default. So I guess it is just an issue with Dell Devices. I think it is better if I try this with Dell's support.