Communicating Applications Spec - Find first queue entry

        Entry:
          AX = CB06h
          DL = queue to search
               00h task queue
               01h receive queue
               02h log queue
        Return:
          AX = 0000h successful
              BX = event handle for found event
              < 0          error code (see AX=CB01h)

        Note: direction of search is same as preceding FIND FIRST call