<a href="link"
target="_blank">link</a>
You will have to edit the template to get it lol.
Sure you can set files to open in browser with hfs, but i find it best to specify them in the template. I do this in the new beta builds of HFS.
[target]
{{switch|{{lower|%item-ext%}}|,|gif,pdf,htm,html,css,js,txt,jpg,png|target="_blank"|}}
and in [file]
the link <a href="moo"
{{$target}}>MOO</a>
You could do it also with javascript.
<a href="javascript:window.open('%item-url%','%item-name%','width=,height=,left=,top=,scrollbars=1,resizable=1');">MOO</a>