Is it possible to use a trusted connection (SSPI) with the SQLDMO API?
See the question and my original answer on StackOverflowSure, you can use the LoginSecure property:
SQLServerClass sqlServer = new SQLServerClass();
sqlServer.LoginSecure = true;
sqlServer.Connect("MyServerName", null, null);
(actually, I don't remember if you must pas null or empty strings...)