It really depends where this html code is coming from but with a lack of that info this is a good place to get you started if you want to play around with some stuff.
<xen:set var="$yourContent">I am a string containing some <b>html</b></xen:set>
{$yourContent}
// output looks like: I am a string containing some <b>html</b>
{xen:raw $yourContent}
// output looks like: I am a string containing some html