решаю по excel9.h
CString sSub;
BOOL blNewXls = FALSE;
int nCol;
int nSheetNum;
int nCnt;
CString strSerialNo,strInspector;
COleVariant VOptional((long)DISP_E_PARAMNOTFOUND, VT_ERROR);
_Application objApp;
_Workbook objBook;
Workbooks objBooks;
Worksheets objSheets;
_Worksheet objSheet;
Range objRange;
Font ft;
LPDISPATCH lpDisp;
if( !objApp.CreateDispatch("Excel.Application") ){AfxMessageBox("XLS ERROR"); return FALSE;}
objApp.SetVisible(TRUE);
objApp.SetUserControl(TRUE);
lpDisp = objApp.GetWorkbooks();
objBooks.AttachDispatch(lpDisp);
lpDisp = objBooks.Open(destFileName, VOptional, VOptional, VOptional,VOptional, VOptional, VOptional, VOptional, VOptional, VOptional, VOptional, VOptional, VOptional);
objBook.AttachDispatch(lpDisp);
lpDisp = objBook.GetSheets();
objSheets.AttachDispatch(lpDisp);
lpDisp = objSheets.GetItem(COleVariant((long)1));
objSheet.AttachDispatch(lpDisp);
objRange = objSheet.GetRange(COleVariant("C2"), COleVariant("C2"));
//excel cell number
sSub.Format("%s", row[0]);
objRange.SetValue(COleVariant(CString(sSub)));