I believe the "white port" you are referring to is the DVI port. The graphics card should have come with an adapter but if not most electronics stores will sell them since DVI is very common. Yes you can use any of the 3 ports for a second screen but only the HDMI port will have video AND audio.
 
Here is a picture of the GT 220 with the DVI circled in red... 
 
 
In Windows 7, right click on your desktop and there should have an option for Nvidia Control Panel. Open that and you should see a menu option on the left for "Setup multiple displays", select that. It will show you all of the displays you currently have connected to the graphics card. Check each display you want to use and then the picture will show up.
 
Here is a screenshot of the Nvidia Control Panel menu showing how I have multiple displays setup. You can grab the numbered box to change the orientation of your displays so that they reflect how they are actually setup in your room.
 

Mor3bane

Thanks blacksapphire,

Knowing the DVI can be utilised for my purpose make me happy.

Incidentally my PC was a shop custom-build from abt 2 years ago so I didnt get all of the extra parts so-to-speak.

About HDMI; I dont really need sound on both displays nor does my current display have speakers (that I want to use). So in that light, the DVI is fully high-res suitable?

Thanks again.

Absolutely, single link DVI supports up to 1920x1200 and dual link DVI supports up to 2560x1600. The GT 220 supports both but you need a display capable of the resolution and the right cable (most DVI cables are single link). You can tell what kind of cable it is by looking at the pins...

by the way blacksapphire - your knowledge and capacity to find resources is quite admirable and i appreciate your input as it has provided me all i need to know about getting this dual setup online.
 
thanks again and happy new year :)