Here it is:
----------------------------------------------------------
user_view.html:
<%if user_homepage%>
<tr>
<td width="20%" align=right valign=top bgcolor="<%light_beige%>" style="border-right:1px solid <%dark_beige%>">
<%body_font%><b>Homepage:</b><%/body_font%>
</td>
<td valign=top bgcolor="<%odd_color%>">
<%body_font%><a href="gforum.cgi?url=<%GT::CGI::escape($user_homepage)%>" target="_blank" rel="nofollow"><%user_homepage%></a><%/body_font%>
</td>
</tr>
<%endif%>
----------------------------------------------------------
Tag: url()
<a href="<%cgi_root_url%>/gforum.cgi?url=%c1%" target="_blank" rel="nofollow">
----------------------------------------------------------
Convert.pm:
if ($GForum::SESSION_TYPE and $GForum::SESSION_TYPE eq 'param') {
$txt .= qq|$save_pre<a href="gforum.cgi?url=$eurl" target="_blank" rel="nofollow">$leading$display_url$trailing</a>$post|;
}
else {
$url =~ s/"/"/g;
$txt .= qq|$save_pre<a href="$url" target="_blank" rel="nofollow">$leading$display_url$trailing</a>$post|;
}
----------------------------------------------------------