Of all the cursor-related APIs, this would probably have to be the least used, so I will only cover it briefly. The API GetClipCursor allows you to retrieve the clipping rectangle. Before continuing, you will need the following API declare and UDT:
Declare Function GetClipCursor Lib "User32" (lpRect As RECT) As Long
Type RECT
Left as Long
Top as Long
Right as Long
Bottom as Long
End Type
Just create a new RECT structure, and then call the API, passing the structure with the lpRect argument. Keep in mind that VB will not let you pass UDTs ByVal.
Note: If the cursor is not constricted by the system, the API will fill the structure with the rectangle defining the screen.