You can get little keypads like this as surplus, or new other places, for not much money, then wire them up using the keypad library
Non-Illuminated Pushbutton Switches - Surplus Sales of Nebraska
Yes i think this will be the last resort if i cant use my existing Keyboard. As i am still learning Electronics so i want to tear up my possessions and learn.
As Westfw posted. If you ditch the actual buttons on the keyboard and use the little PCB that does the keyboard matrix decoding you can easily figure out which points on the PCB to connect to simulate a keypress.
Yes you are right, there is a Keyboard Controller inside my Keyboard but dont know how to use that, i ll Google for it but if you have some nice tutorials on how to use Keyboard controllers with Arduino, do post.