translating and commenting punctuation [XSLT1.0]

Hello everybody,

I am trying to translate "," in text to new line while keeping a copy of 
it in comment. Some thing like below:

XML
===

<mytext>xxxx, yyyy, zzzzz, ttttt</mytext>

Output Required
==========

<mytext>xxxx<!--,-->
 yyyy<!--,-->
 zzzzz<!--,-->
 ttttt</mytext>


XSLT
====

    <xsl:template match="mytext">
        <xsl:copy>
            <xsl:copy-of select="@*"/>
           <xsl:value-of select="translate(.,',','&#x000A;')"/>
        </xsl:copy>
    </xsl:template>

This does the trick just to get hard enter but of course do not generate 
the commented comma. I tried of using concat() along with translate but 
that doesn't seems to be working. Shall I need to write another rule for 
commenting the commas. I do not wish to do that as this is required for 
this element only. 

Any clue will be great to get this done. Comment is required just for 
repurposing.

Best,
--PC