[xsl] XPath questions: selecting from an attribute node axis and an attribute name variable

["Mark" <mark@xxxxxxxxxxxx>]

Hi,
I am using XSLT 2.0. and have two questions I have been unable to resolve:

(1) An attribute name variable:
Is it possible to write
   <xsl:for-each select="../Stamp/Formats/@souvenir-sheet">
in such a way that @souvenir-sheet is replaced by a variable representing 
other attributes so that the same statement could be used to service a 
different specific <Formats> attribute?  i.e, xsl:for-each 
select="../Stamp/Formats/@minisheet"> "Any" will not work, the name has to 
be specific.

(2) Selecting from the attribute axis:
> From within the context provided by the execution of
   xsl:for-each select="../Stamp/Formats/@souvenir-sheet">
 in the <Stamp> element below , is it possible to select the element 
<CatNumber>'s attribute: pofis-number?
i.e.,
   <xsl:variable name="file-name" select="concat([some XPath 
expression?]CatNumbers/@pofis-number, '.htm')"/>

XML fragment
<Stamp>
     <CatNumbers scott-number="3040" scott-suffix="a" pofis-number="174"/>
      <Formats souvenir-sheet="174"/>
</Stamp>

I really hope the answers are yes and that you can tell me how.  I tried to 
find this info in Michael's book, but failed.

Thanks,

Mark