I want to know the best solution for this

my case here is that i am taking values from Excel sheet and pushing them to database field, sometimes that field might contain some strings (thats why I cant make my object members int / double)

In my class below size is the variable responsible for showing size of files in bytes

public class dataNameValue
{
    public string Name { get; set; }
    public string Count { get; set; }
    public string Size { get; set; }
}

I wanted to sort the list by file Size something like

List mylist = new List(); mylist = mylist.OrderByDescending(i => i.Size).ToList();

The problem is that if i sorted it without converting it to "int/double" first -- its not giving right results