Class names of Windows controls can be looked up with different tools, like Spy++, AU3_Spy.
When using AU3_Spy ...
- activate the window with the desired control/area (failing to do so will lead to wrong or lack of information),
- hover the mouse over the desired control/area,
...then the class name is displayed in the section "Now Under Mouse Cursor":
Note that the class names have number postfixes which must be stripped off. But at the same time, numbers can be part of the class names, for example SysTreeView32, as shown in this example. To find out whether the numbers are part of the class name or not you may need to try all possible variants, but in most cases assuming the "32" is part of the class name is a pretty safe assumption.
Related Information: