C++ excel example https://github.com/tfussell/xlnt

Main.cpp

#include <xlnt/xlnt.hpp>
#include <iostream>

void create() {
	xlnt::workbook wb;
	xlnt::worksheet ws = wb.active_sheet();
	ws.cell("A1").value(5);
	ws.cell("B2").value("string data");
	ws.cell("C3").formula("=RAND()");
	ws.merge_cells("C3:C4");
	ws.freeze_panes("B2");
	wb.save("sample.xlsx");
}

void read() {
	xlnt::workbook wb;
	wb.load("sample.xlsx");
	xlnt::worksheet ws = wb.active_sheet();

	std::cout << ws.cell("A1") << std::endl;
	std::cout << ws.cell("B2") << std::endl;
	std::cout << ws.cell("C3") << std::endl;
}

int main()
{
	create();
	read();
	return 0;
}

git clone https://github.com/tfussell/xlnt.git -b v0.9.1 --recurse-submodules
cd xlnt
mkdir build
cd build
cmake -D STATIC=ON -G "Visual Studio 14 2015 Win64" ..
cmake --build .

std::string ch = ws.cell("A1").value<std::string>();
double dh = ws.cell("A1").value<double>();