C / C++ / MFC

void replace_all(wstring& target, const wstring& to_find, const wstring& replacement )
{
   if (to_find.empty())
      return; 
   
   size_t replace_inc = replacement.length();
   for (size_t loc = target.find( to_find ); 
      loc != wstring::npos; 
      loc = target.find( to_find, loc + replace_inc ) )
   {
      target.replace( loc, to_find.length(), replacement );
   }
}

If you can ensure excel will be installed on the machine(s) where your program will run, you can use Excel's COM interface to create a new worksheet: (example for Excel 97)

#import "C:\Program Files\Microsoft Office\Office\MSO97.DLL"
#import "C:\Program Files\Common Files\Microsoft Shared\VBA\VBEEXT1.OLB"
#import "C:\Program Files\Microsoft Office\Office\EXCEL8.OLB" \
        rename("DialogBox","_DialogBox") \
        rename("RGB","_RGB") \
        exclude("IFont","IPicture")

using namespace Excel;

_ApplicationPtr pApp(__uuidof(Application));
pApp->Workbooks->Add();

pApp->PutVisible(TRUE);

For more information on manipulating Excel via COM, see the MSDN documentation. For more on using the Excel COM interface from Visual C++, see Igor Tkachev's article Using MS Office in an MFC Application.