Merging multiple xmls into a single xml

Hi,

I want to merge multiple xmls into a single xml. Here are the details:

The number of input xmls is not fixed, it may vary. So is it possible
to accept more than one input file to an xsl script?
Alternatively, using -PARAM, can I specify more than one variable to
be passed as command line parameter to xsl script?

Each of this input xml would contain a node:
<module name="x">
  <mod_props height="2" width="3"/>
</module>

Final output xml would look like:
<modulenames>
 <global_mod_prop color="black"/>

<module name="x">
  <mod_props height="2" width="3"/>
</module>

<module name="y">
  <mod_props height="5" width="4"/>
</module>

</modulenames>

any help would be greatly appreciated.

Thanks,
Neelam