Problem with importing certain columns of a MS Project file into RTC

I've been able to get links (predecessor, parent, child, etc.) to import from an excel file by labeling the column with the correct link name and putting a "#" sign followed by the work item ID.  But these Predecessors are the line item from the Project file, so not the same as the ID for the RTC work item.

Still have the issue of not having the WBS field not showing up in the RTC task.  The interesting thing is that I saved a project file in XML.  Then imported it into RTC.  Then I went to that plan in RTC and exported the plan into an XML file.  Interestingly, it saves the MS Project information somewhere within RTC because it exported the WBS and other data into my new XML file.  Therefore, it is storing it someplace in RTC.  How do I get the WBS field to show up on an RTC task work item?

Here is an excerpt of one of the tasks as exported from RTC into XML (with an origin of being saved as a MS Project XML file and imported into RTC to create the task):

<Task>

<UID>6</UID>

<ID>6</ID>

<Name>Input expenditures for contractor personnel - November</Name>

<Type>0</Type>

<IsNull>0</IsNull>

<WBS>1.1.1.1.1.1</WBS>

<OutlineNumber>1.1.1.1.1.1</OutlineNumber>

<OutlineLevel>6</OutlineLevel>

<Start>2014-08-04 14:18:44</Start>

<Finish>2014-08-05 14:18:44</Finish>

<Work>PT8H0M0S</Work>

<Duration>PT8H0M0S</Duration>

<RemainingDuration>PT8H0M0S</RemainingDuration>

<ActualStart/>

<ActualFinish/>

<ActualDuration>PT0H0M0S</ActualDuration>

<ActualWork>PT0H0M0S</ActualWork>

<Milestone>0</Milestone>

<Summary>0</Summary>

<FixedCostAccrual>3</FixedCostAccrual>

<PercentComplete>0</PercentComplete>

<ConstraintType>4</ConstraintType>

<ConstraintDate>2014-11-15T08:00:00</ConstraintDate>

<HyperlinkAddress/>

<Notes/>

<Deadline/>

<ExtendedAttribute>

<FieldID>188743734</FieldID>

<Value>New</Value>

</ExtendedAttribute>

<ExtendedAttribute>

<FieldID>188743737</FieldID>

<Value/>

</ExtendedAttribute>

<ExtendedAttribute>

<FieldID>188743945</FieldID>

<Value/>

</ExtendedAttribute> -

<ExtendedAttribute>

<FieldID>188743767</FieldID>

<Value>3711</Value>

</ExtendedAttribute>

<ExtendedAttribute>

<FieldID>188743740</FieldID>

<Value/>

</ExtendedAttribute>

<PredecessorLink>

<PredecessorUID/>

<Type>1</Type>

<CrossProject>0</CrossProject>

<LinkLag>0</LinkLag>

<LagFormat>7</LagFormat>

</PredecessorLink>

</Task>

As you can see the WBS number is stored somewhere since it is showing up in the XML export from RTC.  How can I get that data into an attribute on my RTC task work item??