As far as I can tell, the changes in the versions of ISO690Nmerical.xsl available from the web only affect Citations (surrounding the author list with square brackets).
If you want to modify the Bibliography so that you get references numbered "[1]" etc. instead of "1." etc., then what you need to do is
find and open the .xsl file (you can use Notepad), and if you have not already make a copy, save a copy. Here, with Word 2016 from Office 365 on Windows 10, it was in
C:\Users\installer\AppData\Roaming\Microsoft\Bibliography\Style
Then , it depends on whether you are using the original ISO690.xsl or ISO690Nmerical.xsl that came with Word, or the one which came from BibWord, which is structured very differently.
(If it is the ISO690Nmerical.xsl that came with Word, if you search for 1029
you should find some code that displays a title in Czech (I'm just jumping to a conclusion based on your sample text). You could usefully modify that display title. But what you really need to look for is
string-length(normalize-space($BibReference))
You should then see some XSL that looks something like this:
<xsl:if test="string-length(normalize-space($BibReference)) > 0">
<xsl:value-of select="b:RefOrder"/>
<xsl:call-template name="templ_prop_Dot"/><xsl:call-template name="templ_prop_Space"/>
<xsl:copy-of select="$BibReference"/>
</xsl:if>
You need to change that so it looks like this:
<!--change reference to look like [1] rather than 1.-->
<xsl:if test="string-length(normalize-space($BibReference)) > 0">
<xsl:text>[</xsl:text><xsl:value-of select="b:RefOrder"/><xsl:text>]</xsl:text>
<xsl:call-template name="templ_prop_Space"/>
<xsl:copy-of select="$BibReference"/>
</xsl:if>
Save the .xsl, change your bibliographic style to something else and back again, then see if your results are updated.
If it's one of the other .xsl s, it may be different. I don't have time to check right now, but have a look and see what you can find out.