This macro is defined as:

#define WinQueryLboxItemText(hwndLbox, index, psz, cchMax)  \
        ((LONG)WinSendMsg(hwndLbox,                         \
                          LM_QUERYITEMTEXT,                 \
                          MPFROM2SHORT((index), (cchMax)),  \
                          MPFROMP(psz)))

This macro requires the existence of a message queue.