Custom Windows password filter - Password communication

Hi,

I am capturing password change event on my DC(source domain) by implementing solution provided here - https://msdn.microsoft.com/en-us/library/windows/desktop/ms721766%28v=vs.85%29.aspx?f=255&MSPPError=-2147217396.

Now I want to send this password, perhaps sets this password on a user on target domain. Now, this target domain is not have trust relationship with source domain. I want to know:-

What it the best and secure solution to implement this?

I am using C#.net and following namespaces:-

System.DirectoryServices, System.DirectoryServices.Protocols and system.directoryservices.accountmanagement