Sort first get sibling later

I have an XML :
...
<numbers>
<number>5</number>
<number>4</number>
<number>9</number>
<number>6</number>
<number>18</number>
<number>33</number>
</numbers>
... 
I need to sort it and also provide prev and next sibling in sorted list... Like this:
<numbers>
<number next ="5">4</number>
<number prev="4" next ="6">5</number>
<number prev="5" next ="9">6</number>
<number prev="6" next ="18">9</number>
<number prev="9" next ="33">18</number>
<number prev="18">33</number>
</numbers>
If I use sorting and "following sibling" then I get sorted list but prev and next elements are as in original list.
So questiuon is how can I sort it first and get siblings in sorted list in one XSL?

Thank you in advance :o)

 XSL-List info and archive:  http://www.mulberrytech.com/xsl/xsl-list