How do I programmatically add a substitution filter for IIS?

All you need to do is add a wild card in the metabase property ScriptMap

site:

For example:

using (DirectoryEntry de = new DirectoryEntry("IIS://Localhost/W3SVC/2/ROOT"))
{
    de.Properties["ScriptMaps"].Add(
        @"*,c:\windows\microsoft.net\framework\v2.0.50727\aspnet_isapi.dll,0,GET,HEAD,POST");
    de.CommitChanges();
}

      

        
        
        
      

    

The above example renders an ASP.NET 2.0 ISAPI filter as a wildcard filter.