Tracking EDI Control Numbers in R2 EDISend Pipelines

After months of working on Biztalk 2006 R2 EDI tracking I'm still not sure how the inbound EDI 997s are correlated to outbound EDI transactions. 

I need to track certain message properties in the outgoing EDI transactions.  For some reason one of our trading partners is not sending 997s for all of the EDI messages we transmit.  But I can query their system and see that the transactions were received.  So my problem is now finding the outbound EDI messages and somehow resolving the open status.

Using HAT I can see certain EDI message properties are created in the EDI assemble pipeline component.  These properties are

<Property Name="InterchangeControlNo" Namespace="http://schemas.microsoft.com/BizTalk/2006/edi-properties" Value="000000059"/><Property Name="InterchangeDate" Namespace="http://schemas.microsoft.com/BizTalk/2006/edi-properties" Value="080604"/><Property Name="ReceiverID" Namespace="http://schemas.microsoft.com/BizTalk/2006/edi-properties" Value="PARTYA "/><Property Name="SenderID" Namespace="http://schemas.microsoft.com/BizTalk/2006/edi-properties" Value="PARTYB "/><Property Name="InterchangeTime" Namespace="http://schemas.microsoft.com/BizTalk/2006/edi-properties" Value="0910"/><Property Name="ReceiverQualifier" Namespace="http://schemas.microsoft.com/BizTalk/2006/edi-properties" Value="ZZ"/>

The schema for these message properties is not included in R2.  So I created a property schema for them and deployed it to my application.  Then I added a ISAControlNumber field to my BAM definition and linked the property schema to my Tracking Profile.

Now when my EDI transactions go out I get the ISAControl number to track down if the EDI transaction was accepted by my trading partner.