using System;

using DocumentFormat.OpenXml.Packaging;

public class Program

{

    public static void Main()

    {

        const string FILENAME = 

                @"C:\SHARE\test.xlsm";

        using (WordprocessingDocument document = 

                    WordprocessingDocument.Open(FILENAME, false))

                {

                    var props = document.ExtendedFilePropertiesPart.Properties;

​

                    if (props.Company != null)

                        Console.WriteLine("Company = " + props.Company.Text);

​

                    if (props.Lines != null)

                        Console.WriteLine("Lines = " + props.Lines.Text);

​

                    if (props.Manager != null)

                        Console.WriteLine("Manager = " + props.Manager.Text);

                }

    }

}