How do I map clearquest user to a different user in RTC when importing CQ records?

I want to be able to map the CQ owner to a different owner in RTC but it always uses the owner from the CQ record.
So in my example below the new Work Item is always owned by admin.
I want to convert admin to my account karl
I'm following Migrating Rational ClearQuest records to work items

Here's my mapping file:
<?xml version="1.0" encoding="UTF-8"?>
<mapping version="1">
    <attribute sourceId="id" targetId="com.ibm.team.workitem.attribute.summary">
    </attribute>
    <attribute sourceId="Owner" targetId="com.ibm.team.workitem.attribute.owner"/>
    <attributeType targetId="contributor">
        <value sourceId="admin" targetId="karl"/>     
    </attributeType>
     <attribute sourceId="Description" targetId="com.ibm.team.workitem.attribute.description"/>
</mapping>

Here's the exported CQ record:

<?xml version="1.0" encoding="UTF-8" standalone="yes" ?>
<bugzilla version="3.3" urlbase="">
<bug>
    <dbid>33554441</dbid>
    <bug_id>CQEXP00000009</bug_id>
    <id>CQEXP00000009</id>
    <Owner>admin</Owner>
    <Description>Test RTC Import</Description>
</bug>
</bugzilla>