template selection based on attributes

Hi,

I've got a 2-column page where I want to display articles in. The articles
appear in both columns. Normally, I would create my XML file in this way:
<Page>
<Col1>
<Article></Article>
<Article></Article>
</Col1>
<Col2>
<Article></Article>
<Article></Article>
</Col2>
</Page>

And the XSLT is pretty simple to produce from here.

But I would like to declare all the articles in a single list and then
decide where to put them as an attribute as such:

<Page>
<Article layoutpos="col01"></Article>
<Article layoutpos="col01"></Article>
<Article layoutpos="col02"></Article>
<Article layoutpos="col02"></Article>
</Page>

And then in the XSLT file itself, find some way to iterate through the list
and selectively display the articles.

<xsl:template match="/Page">
<div class="col01">
###Call template for Article but filter for col01###
</div>
<div class="col02">
###Call template for Article but filter for col02###
</div>
</xsl:template>

Is there a way to do this?

Thanks!
Wong