The only way to do this without trying to inject javascript is to hide the default page title element with CSS and recreate the page title in your page source and style it to match the site's page title element. For example:
[[module css]]
#page-title {
/* hide the default page-title element */
display: none;
}
.page-title {
/* duplicate the ID selector for the page-title as a CLASS selector */
margin: 0 0 0.5em 0;
padding-top: 0.5em;
font-size: 180%;
border-bottom: 1px solid #666;
}
[[/module]]
[[div class="page-title"]]
Italicizing //Part of the Title// with CSS
[[/div]]
> Lorem ipsum dolor sit amet, consectetur adipiscing elit. Donec velit ligula, rutrum ac odio non, imperdiet posuere orci. Nunc faucibus faucibus neque. Curabitur ac erat placerat, hendrerit nisi et, viverra lectus. Cras at tellus quis dolor tempor blandit ac sed augue. Donec ut dapibus odio, id fermentum velit. Aliquam molestie facilisis mattis. Phasellus malesuada cursus libero, eu dignissim risus venenatis non. Integer varius ut metus eu elementum. Nullam at odio ut nisi maximus aliquet quis at metus. Nulla tristique nisl eros, in consequat sem tincidunt eu.
Pellentesque vitae rhoncus elit. Phasellus ultricies ipsum ut tempus laoreet. Nunc varius augue vel risus euismod, ut sagittis tortor ullamcorper. Suspendisse eu pretium felis. Integer eu odio ornare, tempus dui sit amet, dictum turpis. Vivamus et dignissim arcu, ut tristique purus.
...
Using this approach, you can easily style the new "title" any way you like using CSS and wiki syntax.
Live example on the playground: http://community-playground.wikidot.com/italicizing-part-of-the-title-with-css