Two content window

I want to make a dictionary
I Want that there will be two column.
In the left column there will be List. This list will contain 500 items.
In the right column, there will be clickable A-Z
So when I click on any letter , in the left column it will scroll to specific anchore.
I know how to use scrollTo function. But I have only problem that When I scroll Left column, Right column also scroll. I want to scroll only left, and right column will be fixed.

is it possible ? plz help