Creating HTML page as single CMS page and want to know how can I use vb:if conditions in it. Is it possible at all?

Code:
<html>
<head></head>
<body>
<vb:if condition="$show['guest']">
Show this to only guest.

<vb:elseif condition="is_member_of($bbuserinfo, 5,6)" />
Show this to user group 5 and 6 which is  mods and admins

<vb:else />
Show this to all registered users

</vb:if>
</body>
<html>