a sequence of regex-group()

Hi all, 

sanity check 

If I wanted a sequence of all the regex-group() values available in a matching-substring... 

(This is inside a function and the actual regex $re is passed in as a param, so number of item() is unknown) 

I expected this to be somewhat more straightforward than this, so I check 

<xsl:variable name="group-count" select="string-length(replace($re, '[^\(]+', ''))"/> 
<xsl:analyze-string select="$str" regex="{$re}"> 
<xsl:matching-substring> 
<xsl:variable name="re-groups" select="for $i in 1 to $group-count return regex-group($i)" as="item()*"/> 


Any thoughts? 

Thanks a lot 

Geert