save excel file in folder in C#

[judithSampathwa]

Hi there,
I have a question regarding excel in C#. I have a datagridview and in that I have a datagridview cell button to open an excel file and make it visible, and another to upload to save the file to a folder in a project folder,
I add the code for openin the excel file which is shown below,

Microsoft.Office.Interop.Excel.ApplicationClass tt = new Microsoft.Office.Interop.Excel.ApplicationClass();

            String path = @"Spreadsheet.xlsx";
            tt.Workbooks.Open(path,0, false, 5, "", "", true, Microsoft.Office.Interop.Excel.XlPlatform.xlWindows, "",
            true, false, 0, true, false, false);
            
            tt.Visible = true;

when the user clicks on the datagridview button cell the excel file opens and then the user can save it anywhere in the computer. Then when the user clicks on the datagridviewbutton cell a open dialog will appear and then the user is able to select the file that was saved in the computer, when the user clicks the ok button the file will be saves making a new folder in the project folder.

How can I do this .
Is there any relevant tutorials I can do on…
thanxxxxxxxxxx