I'm trying to write an exit module for the Microsoft Certificate Authority
in C#.

I've wrapped certxds.dll to an interop and implemented the CCertExit
Interface

Then registered the dll using the following
regsvcs MyExitModule.dll
regasm MyExitModule.dll
gacutil /i MyExitModule.dll

but Certificate Authority doesn't see my exit module.
I assume that com isn't aware that I'm inheriting CCertExit

How do I get C# to tell COM that it's inheriting the COM CCertExit interface

Here is an example

internal enum ExitEvent : int
{
   Invalid = 0x0,
   CertIssued = 0x1,
   CertPending = 0x2,
   CertDenied = 0x4,
   CertRevoked = 0x8,
   CertRetrievePending = 0x10,
   CRLIssued = 0x20,
   Shutdown = 0x40
}

public class Exit : CERTEXITLib.CCertExit
{
   public string GetDescription()
   {
       return "MyExitModiue";
   }

   public Int32 Initialize(string strConfig)
   {
       Logger.Log(LOGINFO, "CA Exit Module initialized.",
SeverityLevel.ImportantInfo);
       return (Int32)(ExitEvent.CertIssued | ExitEvent.CertPending |
ExitEvent.CertDenied | ExitEvent.CertRevoked | ExitEvent.CertRetrievePending

   }

   public void Notify(Int32 exitEvent, Int32 context)
   {
          //DO Stuff....
   }
}