You can also use the Order/Group to group controls in your dialog box. This allows the user to cycle the focus through the members of a group using the arrow keys after moving to a group member with the TAB key.
To be grouped together, controls must be contiguous in the Order/Group list box. Hence you should define groups only after you have the tab order set as you want it.
Groups are shown by lines separating the control names in the list box.
If you have more than one logical group of radio buttons within a dialog, you should group them here so that system will handle their logic properly.