Sorry, this is an old question, but for the sake of people who are looking for the answer to this question: you can use span or div macros and use custom CSS to apply whatever style you want to their content.
If necessary, you can create custom div and span classes to use multiple styles to select text.
EDIT: Here is an example of wikimarkup that you could use for this.
{div:class=customCss|style=float:left; margin-right:50px} Custom text in a div {div}
That way you can use the div class and apply the style in custom css for the merge space, or you can use the inline style for the div.
Mnrsullivan
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