XML processing question

[Rahul]

Hi,

I want to do the following

<A>
<B attr1="1" attr2="2">
............... ..
</B>
<B attr1="4" attr2="5">
............... ..
</B>

............... .......
<B attr1="1" attr2="2">
<repeat attr1="1" attr2="2 // Here I want to insert the
first <Belement which had attr=1 and attr=2
</B>
</A>

The problem is to replace the <repeatelemen t with the sibling of its
parent (repeat will always be done for the sibling of parent of
repeat) which has the given attribute values.

Can I do this in DOM, or I need to pre process the XML using XSD.

Thanks in advance
Rahul