I see that this is an old question, but I'm putting this here because it may come to help someone yet.
You cannot read an attribute in css counter properties.
Instead, you could use inline css with counter-reset
to define the starting number for a particular list.
(Yes, I know it is not a best practice to use inline css, but it can and should be used for edge cases like this one)
The first item increments the reset value by 1, so besides providing the counter name, you will need to subtract the number you want the list to start at by 1:
HTML
<ol>
<li>Number One</li>
<li>Number Two</li>
<li>Number Three</li>
</ol>
<!-- NOTE: List numbering starts at counter-reset + 1 -->
<ol style="counter-reset: lis 9;" start="10">
<li>Number Ten</li>
<li>Number Eleven</li>
<li>Number Twelve</li>
</ol>
CSS
ol {
list-style-type: none;
counter-reset: lis; /* Resets counter to zero unless overridden */
}
li {
counter-increment: lis
}
li:before {
content: counter(lis)". ";
color: red;
}
FIDDLE (http://jsfiddle.net/hcWpp/308/)
[EDIT]: kept start attribute as suggested to address accessibility and progressive enhancement
ol[start="10"] { counter-increment: lis 9; }
will work, but I would like to have a generic way. – Archean