将整数转换成EXCEL里的列标记的函数，如AA，AB，AC

CString IntToABC(UINT nNum)
{
 short nTemp = nNum % 26;
 TCHAR cCur = 'A' + nTemp;
 CString strRet;
 if(nNum / 26 > 0) strRet = strRet + IntToABC(nNum / 26 - 1) + CString(cCur);
 else strRet = CString(cCur);
 return strRet;
}

ASSERT(IntToABC(1000) == "ALQ")