Team Foundation Server -> Microsoft Project integration

I am hoping someone here can shed light on my problem. I am trying to integrate TFS work items and MS Project. What field is mapped from the work item into the duration column of Project? I can change the way I am doing this, but, I had created a custom field Work Item field in TFS. I have the mapping file that TFS uses to map to Project. Here is my Work Item definition:

<FIELD name="EstCodingHours" refname="CustomFields.EstCodingHours" type="Double" 
       reportable="detail">
   <HELPTEXT>Enter estimated number of hours to fix bug</HELPTEXT>
</FIELD>

Here is my mapping definition:

<Mapping WorkItemTrackingFieldReferenceName="CustomFields.EstCodingHours" 
         ProjectField="pjTaskDuration" ProjectUnits="pjHour" />

I can m开发者_如何学运维ap to other fields such as pjTaskDuration1. Is pjTaskDuration read only perhaps? If I can figure out what maps into pjTaskDuration, I can use it instead of my new field EstCodingHours.

Thanks, Scott

The TFS out-of-the-box templates don't map the duration field by default.

Wes Macdonald steps through the process of doing such a mapping in a blog post.