Question

Can I generate COM visible assemblies (using CodeDom, or anything else) ?

I am looking to expose C# classes to VBA. Basically, I have an object-driven web server, and everytime I build my web server, I would like to also generate some wrapping classes (COM visible using CodeDom) as some clients will need these to access data from other contexts (Excel/VBA, etc…).

So is this possible at all ?

UPDATE:
Trying the RegFree approach of Snoopy, I build that class into test2.dll with CodeDom:

   namespace Test
   { 
       public class TestClass
       {
        private double _d1;
        private double _d2;

              public double d1 {
                get { 
                  return _d1; }
                set { _d1 = value; }
              }

           public double d2 {
            get { return _d2; }
            set { _d2 = value; }
           }

           public double sum()
           {
            return d1 + d2;
           }
       }
   }

I get the following in VBE:

Answer 1

Yes, this is possible using Register Free COM.

1)Open Excel and add the following references

C:\Windows\Microsoft.NET\Framework\v4.0.30319\mscoree.tlb (Common Language Runtime Execution Engine 2.4 Library)

C:\Windows\Microsoft.NET\Framework\v4.0.30319\ mscorlib.tlb

Add your Code Dom generated Classlibrary to the same directory where the Excel Sheet is stored

3)use the following VBA Code:

Sub Command1_Click()
     Dim clr As CorRuntimeHost
     Dim domain As AppDomain
     Dim objTest As Object
     Dim fltResult As String

     Set clr = New CorRuntimeHost

     clr.Start
     clr.GetDefaultDomain domain
     Set objTest = domain.CreateInstanceFrom("C:\Bla\YourGeneratedClassLibrary.dll", "NetComClassLibrary.Info").Unwrap
     fltResult = objTest.Version
     clr.Stop

     '//Debug.Print fltResult
     MsgBox fltResult
 End Sub

More infos:
http://blogs.msdn.com/b/junfeng/archive/2006/04/20/579748.aspx