Ok this is for the control freaks out there (you know who you are). You can place CVs at exact coordinates as you create them. After creating the first CV, open the channel box and select CVs under the shape node or open the attribute editor and expand the components flag. Both of these will give you the fields to enter specific X, Y, and/or Z coordinates. As a tie-in, remember that you can press the middle mouse button to switch to the move manipulator for the current CV, allowing you to position it before creating the next CV. Add to that Jango's Alt + arrows to nudge control.