Create an Excel object.

e = actxserver('Excel.Application');

Add a workbook.

eWorkbook = e.Workbooks.Add;
e.Visible = 1;

Make the first sheet active.

eSheets = e.ActiveWorkbook.Sheets;
eSheet1 = eSheets.get('Item',1);
eSheet1.Activate

Put MATLAB data into the worksheet.

A = [1 2; 3 4];
eActivesheetRange = get(e.Activesheet,'Range','A1:B2');
eActivesheetRange.Value = A;

Read the data back into MATLAB, where array B is a cell array.

eRange = get(e.Activesheet,'Range','A1:B2');
B = eRange.Value;

Convert the data to a double matrix. Use the following command if the cell array contains only scalar values.

B = reshape([B{:}],size(B));

Save the workbook in a file.

SaveAs(eWorkbook,'myfile.xlsx')

If the Excel program displays a dialog box about saving the file, select the appropriate response to continue.

If you saved the file, then close the workbook.

eWorkbook.Saved = 1;
Close(eWorkbook)

Quit the Excel program and delete the server object.

Quit(e)
delete(e)