changing the starting position of animation using subroot?

omg i got it to work. I'm posting and answering my own question here because I hope it will help others who are having the same problem. looking through old thread is very helpful for me when Im learning. so here it goes.
I used this constrain in the interaction tuning
<L n="_constraints">
<U>
<L n="constraints">
<U>
<V n="value" t="position">
<U n="position">
<U n="relative_position">
<T n="z">0.2</T>
<T n="x">1.1</T>

</U>
</U>
</V>
</U>
</L>
</U>
<U>
<L n="constraints">
<U>
<V n="value" t="facing">
<U n="facing">
<T n="range">20</T>
<V t="enabled" n="subroot_index">
<T n="enabled">1</T>
</V>
</U>
</V>
</U>
</L>
</U>
</L>

and in object tuning I added a part data
<L n="_part_data">
<U>
<T n="part_definition">10761394754739631109<!--objectPart_Basketball_Layup--></T>
<V n="subroot_index" t="enabled">
<T n="enabled">1</T>
</V>
</U>
</L>

the tuning ID in the part data referrers to this object part tuning

<?xml version="1.0" encoding="utf-8"?>
<I c="ObjectPart" i="object_part" m="objects.part" n="pandasama:TB_part_1" s="10761394754739631109"></I>

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