Positioning dynamic controls

I have a control dereived from CWnd that I want on my CFormView (using a dialog template). I am creating this control dynamically in the OnCreate, however I do not want to use "trial-and-error" to figure out the coordinates at where this control should be positioned. I would like to use a visual control in the Resource Editor, so that the position is precise, but which control do you use for a generic-CWnd control? Do I then use the DDX_Control to link the control? If I use "trial-and-error" to find the coordinates, these will be different in large font mode, because the dialog layout units are different when you switch modes. Any help would be appreciated. Email me (Dan) at [email protected]. Thanks in advance!!!