conditional mapping of node-elements

Hello experts,

i've a simple mapping question:

Dest. Node:

<src_node> occurrence 1:n

<qualifier>

<value>

</dest_node>

<dest_node> occurrence 1:n

<qualifier>

<value>

</dest_node>

Mapping:

<src_node> -

> <dest_node>

This means 10 source nodes produce 10 destination nodes. No problem so far.

But how do tell the mapper just to generate these dest_nodes where the field <i><b>qualifier</b></i> of each occurence of src_node is i.e. "XX"?

Is it possible to do this by standard functions or do i need to write UDF?

Regards

Gunnar