How can I find Scroll Bar Code; How does it get created?

There is a datagridview in my application where a scroll bar is being created at runtime. I need to make some modification to the scroll bar (need to make it shorter to position a page-up page-down bottom on top and bottom of the bar)

having a difficult time finding the sourcecode where the scroll bar gets created. I went into debugging mode to find that out however it is like a ghost and it shows up when gridview populates.

Any Help or information is appreciated.