How to pass a nodeset as parameter

Hi all...

I'm trying to pass a nodeset as parameter to a template.

I'm doing this when I apply the template:

<xsl:with-param name="cob_rowset"
select="/propuesta/cob_excluyentes/ROWSET/ROW[CXC_CAD_ID=current()/CAD_ORI_ID
]" />

when I display
count(/propuesta/cob_excluyentes/ROWSET/ROW[CXC_CAD_ID=current()/CAD_ORI_ID]),
it displays 2, meaning that 2 rows exist.

When I use count($cob_rowset) in the template, it sends the error $cob_rowset
isn't a nodeset.

Any help will be greatly appreciated

Thanks
Jaime