identifying the specific comments associated with an element

I would like to process data that is in the following format.

<dataItems>
     <!-- this is a comment about the first item -->
     <item name="itemName1">I1</item>

     <!-- this is a comment about the second item -->
     <!-- this is a follow on comment for 2nd item -->
     <item name="itemName2">I2</item>

     <!-- this is a comment about the third item -->
     <!-- 3rd item also has an additional comment line -->
     <item name="itemName3">I3</item>

     <!-- this is a comment about the fourth item -->
     <item name="itemName4">I4</item>
</dataItems>

In particular I would like to be able to  process one item at a time as
is customarily done with <xsl:apply-templates select="/dataItems/item" />

What I don't understand how to do is associate  the comments with the 
appropriate data items.
For instance, how would I process this data to convert the comments into 
attributes as follows:
<dataItems>
     <item name="itemName1" comment="this is a comment about the first 
item">I1</item>
     <item name="itemName2" comment="this is a comment about the second 
item. this is a follow on comment for 2nd item">I2</item>
     <item name="itemName3" comment="this is a comment about the third 
item. 3rd item also has an additional comment line">I3</item>
     <item name="itemName4" comment="this is a comment about the fourth 
item">I4</item>
</dataItems>

Or how would I select the item whose name is "itemName3" along with it's 
comments? i.e call
<xsl:apply-templates select="/dataItems/item/[(_at_)name = 'itemName3']" /> 
and within the item template grab the comments
     <!-- this is a comment about the third item -->
     <!-- 3rd item also has an additional comment line -->


Thanks,
ap