Here is code to add a link. Maybe someone else can figure out how to get it to actually display. This link is for your navbar.
HTML Code:
<tr><td class="vbmenu_option">
<if condition="$bbuserinfo[fieldXX]">
<a href = "http://www.weather.com/weather/local/$bbuserinfo[fieldXX]?lswe=$bbuserinfo[fieldXX]&lwsa=WeatherLocalUndeclared&from=whatwhere">weather</a>
</if>
Replacing XX with the field that you set in the ACP.