See this link on how to get the type:
http://support.microsoft.com/kb/320523
See this SO answer regarding COM objects and reflection:
https://stackoverflow.com/a/10617479/4004002
Also, do you know what the properties are ahead of time? If so you may (I've never tried it with a COM object) be able to use Dynamics instead to access the properties.
dynamic d = simObjects;
string myVariable = d.SomeProperty;
EDIT: This link explains using dynamics and COM
http://msdn.microsoft.com/en-us/magazine/ff714583.aspx
In case it disappears:
public static class WordDocument
{
public const String TemplateName = @"Sample.dotx";
public const String CurrentDateBookmark = "CurrentDate";
public const String SignatureBookmark = "Signature";
public static void Create(string file, DateTime now, String author)
{
// Run Word and make it visible for demo purposes
dynamic wordApp = new Application { Visible = true };
// Create a new document
var doc = wordApp.Documents.Add(TemplateName);
templatedDocument.Activate();
// Fill the bookmarks in the document
doc.Bookmarks[CurrentDateBookmark].Range.Select();
wordApp.Selection.TypeText(current.ToString());
doc.Bookmarks[SignatureBookmark].Range.Select();
wordApp.Selection.TypeText(author);