You need to have installed Microsoft Visual Studio Tools for Office (VSTO).
VSTO can be selected in the Visual Studio installer under Workloads > Web & Cloud > Office/SharePoint Development.
After that create a generic .NET project and add a reference to Microsoft.Office.Interop.Excel
via ‘Add Reference… > Assemblies’ dialog.
Application excel = new Application();
Workbook wb = excel.Workbooks.Open(path);
Missing.Value
is a special reflection struct for unnecessary parameters replacement
In newer versions, the assembly reference required is called Microsoft Excel 16.0 Object Library
. If you do not have the latest version installed you might have Microsoft Excel 15.0 Object Library
, or an older version, but it is the same process to include.