Programmatically set partner record for Azure

I am looking for a way to programmatically set a write partner for an Azure subscription. Currently, the only way is to use the UI:

http://blogs.technet.com/b/uspartner_ts2team/archive/2015/01/19/microsoft-azure-and-partner-of-record.aspx

Is there a way to do this using API command line tools, powershell, or Azure?