Sets or retrieves the corner radius value on the General | Appearance tab of the Object Properties dialog for the current object. This is only supported on rectangle objects.
Defines the radius of the corner. Values from 0- 32 pixels are permitted.
If retrieving the current corner radius, a value between 0 and 32. If applying a corner radius, 0 (zero) if successful. In both cases, an error is returned if unsuccessful. If values are out of range on writing to the attribute, the function exits and reports the error E_INVALIDARG. If there is no active object, they exit with a return value of E_HANDLE.