> I thought to 
> "from" attribute of xslt:number, but it doesn't work. can you help me?

I haven't tried to understand your problem (it involves too much digging
around previous messages), but there is no option in xsl:number to start
numbering at a value other than one. If you guessed that the from attribute
would do this, then you guessed wrong (and it's best not to guess). What you
can do is:

<xsl:variable name="n" as="xs:integer">
  <xsl:number (options excluding format)/>
</xsl:variable>
<xsl:number value="$n+6" format="..."/>

Regards,

Michael Kay
http://www.saxonica.com/
http://twitter.com/michaelhkay