[V8i C++] Using Standard PUSHBUTTON_OK in Modal DialogBox

I've got a modal DialogBox that includes the built-in PushButtons PUSHBUTTON_OK and PUSHBUTTON_Cancel. I'd like to (somehow) attach a hook function to these so when they are pressed, I can do some checking. Can a hook callback somehow be attached in the DialogItem listing in the DialogBoxRsc?

{{2*XC, GENY(6.8), BUTTON_STDWIDTH, 0}, PushButton, PUSHBUTTONID_OK , ON, 0, "MyHookHere?", "MyHookThere?"},

Bruce