given the xml
<vs>
<ve pos="1"></ve>
<ve pos="1.1"></ve>

and given that i am starting on a node with pos=1 (or 2 or 3....), how do i count the nodes which have position with 3 dots only (e.g. pos=1.1.2.1?) and start with the current node position. I came up with something like this:

<xsl:variable name="rowspan" select="count(ve[starts-with(@position, current()/@position) and contains(...........)])" />
e.g. for position 1, it should be 4 (1.1.1.1 , 1.1.1.2, 1.1.1.3, 1.2.1.1)

If there are only digits beside the dots in the pos string, try
 string-length(translate(@pos,'1234567890',''))=3