Hi,

it would be much easier to help you if we could see 
your XML input file and the XSL you have so far...

Maybe you could write a template for the table cells, 
that only gets called on the first of a series,
and sets the colspan attribute something like:

<td colspan="{count(following-sibling::*[.=current()/.])+1}">
    <xsl:value-of select="."/>
</td>

Best regards
Anton Triest