object = accCheckButton(wndID);
Will search for a child accessible object having the ROLE_SYSTEM_CHECKBUTTON role.
This object represents a check box control. Its default action (accDoDefaultAction) cycles the check box through its checked-unchecked-indeterminate states. The current state can be determined using accIsChecked and accIsMixed (for the third, indeterminate state).
wnd Overview | MS Accessibility