Say you want to count like this in mediawiki (not starting at 1):
The internet tells you it's not possible natively and that you need an extension. Here's an ugly hack to do it anyway! (keeping the # rather than going full HTML).
<div style="color:white;"> # <ol start=3><div style="color:black; position:relative; left:-50px;"> # Three # Four # Five</div></ol></div>
It's ugly and could break your document! Use with care under desperate circumstances!