i believe you should read this
link[
^]
in your creation you would have to assign an control id. in your case you have used
0x1448,
Better define a macro something like this
#define IDC_CALIBERBOX 0x1448
then in Create use IDC_CALIBERBOX instead the actual number(reason to do this to avoid some issue of change. say if you need to change only place you will have to change is in the macro definition)
and in your
DDX_Control(pDX,IDC_CALIBERBOX, m_wndCaliber);
DDX_CBString(pDX,IDC_CALIBERBOX, m_sCaliber);