Jasper: Concatenate strings from different xsl nodes in iReport

Let's suppose the following XML used as a datasource in a Jasper report:

<B>
    <C>text1</C>
    <C>text2</C>
    <C>text3</C>

    <List number="1">
        <ListElement1 key="k1" />
        <ListElement2 key="k2" />
    </List>

    <List number="2 />
</B>

<B></B>
<B></B>

In a report list element which lists nodes, i'd like to print C texts concatenated as "text1, text2, text3", but there are some problems:

• It is no possible to use Xpath functions in datasets.


• Also, using the Report query in iReport doesn't let me define fields from relative paths, such as ../../C from List.

Is there a straightforward way to do this? I mean, not using subReports and anything like that.