There is no "right click" ability to add these.
You have to either get custom .xml files or customize it yourself. You don't have to add custom graphics, just need custom layout files.
<LINK REL=STYLESHEET TYPE="text/css" HREF="http://www.gpcentre.net/style.css" TITLE="Cool">
<DIV ALIGN=CENTER>
<TABLE BORDER=0 CELLSPACING=2 CELLPADDING=0 WIDTH=90%>
<TR>
<TD COLSPAN=4 ALIGN=CENTER style="font-weight: bold">This game has warped my fragile little mind.</td></tr>
<TR>
<TD ALIGN=CENTER WIDTH=33% CLASS="mysig">
Sithr (http://www.magelo.com/eq_view_profile.html?num=2572)
60th Iksar Grandmaster
</td>
<TD COLSPAN=2 ALIGN=CENTER WIDTH=34% CLASS="mysig">
Xield Da`Margorach (http://www.magelo.com/eq_view_profile.html?num=1301)
54th Teir`Dal Heretic
</td>
<TD ALIGN=CENTER WIDTH=33% CLASS="mysig">
Lvarin Geirtu`Dal (http://www.magelo.com/eq_view_profile.html?num=1302)
32nd Tu`Dal Bard
</td>
</tr>
<TR>
<TD COLSPAN=2 ALIGN=CENTER WIDTH=33% CLASS="mysig">
Zabies (http://www.magelo.com/eq_view_profile.html?num=3367), 25th Iksar Shaman
</td>
<TD COLSPAN=2 ALIGN=CENTER WIDTH=33% CLASS="mysig">
Rryn (http://www.magelo.com/eq_view_profile.html?num=186874), 24th Iksar Beastlord
</td>
</tr>
<TR>
<TD colspan=4 class="mysig" align=center>Crimson Watchers (http://www.crimson-watchers.org/) - Mithaniel Marr</td>
</tr>
</table>
</div>
</p></p>