Wiring a keyboard hack?

[RecycledPast]

For my first project I used an IPAC but I'd like to replace it with something cheaper since the control panel is only 1 player with a total of 5 buttons (p1 start , p2 start , coin,  p1b1, p1b2)

I've torn apart the keyboard, mapped the matrix, and soldered an IDE cable to it.  I assume I won't have to worry about ghosting since it's such a simple cp.

I'm wondering how to actually wire it up to the buttons.  For example, how do I connect up the player one start button which is the key 1.

Do I connect the two wires that make up the key 1! to NO on the push button? But what about a ground?  Or do I connect one of the wires to the NO and the other to the common  contact?

[JustMichael]

Since you have mapped the matrix you are almost done.  Connect one of the pins that makes "p1 start" to the NO tab of a microswitch.  Now connect the other pin that makes "p1 start" to the COM tab on the microswitch.  Do this for each button.