How can i pass the parameter dynamically using linq?

private List<string> GetAllFieldValues(string p) {     List<string> field_values = new List<string>();     string connectionString = ConfigurationManager.ConnectionStrings["SchoolContext"].ConnectionString;     using (SqlConnection con = new SqlConnection(connectionString))     {         SqlCommand cmd = new SqlCommand();         con.Open();         cmd.CommandText = "SELECT " + p + " from tbl_student where institutionid=" + Convert.ToInt32(Session["institutionId"].ToString());         cmd.Connection = con;         SqlDataReader dr = cmd.ExecuteReader();         if (dr.HasRows)         {             while (dr.Read())             {                 if (p == "dateofadmission" || p == "dateofbirth")                     field_values.Add(Convert.ToDateTime(dr[0].ToString()).ToShortDateString());                 else                     field_values.Add(dr[0].ToString());             }         }         else         {           }     }     return field_values; }

this is my ADO.NET code how can i convert this one to linq i have an idea to change linq but i don't know pass the parameter dynamically.

DataTable dt = new DataTable(); 
 
dt.Columns.Add("company"); 
dt.Columns.Add("firstname"); 
dt.Columns.Add("name"); 
 
dt.Rows.Add(new object[] { "Facebook", "Mark", "Zuckerberg" }); 
dt.Rows.Add(new object[] { "Microsoft", "Bill", "Gates" }); 
dt.Rows.Add(new object[] { "Microsoft", "Steve", "Ballmer" }); 
dt.Rows.Add(new object[] { "Oracle", "Larry", "Ellison" });

string Dynamiccompany="Microsoft

";

IEnumerable query = 
    from contact in dt.AsEnumerable() 
    where contact.Field("company") ==

Dynamiccompany


    select contact;