[davidw]

If you are referring to the postbit, then yes. All you have to do is go edit that in your Styles & Templates area / Style Manager / Style Choice / Edit Templates
In Postbit Templates:
I use postbit_legacy so I'll use that for example.
Find <!-- post $post[postid] popup menu -->
This is the area towards the end of the postbit where it controls what goes in the popup menu.

Find:

<if condition="$post['userid'] AND $show['member']">
	<tr><td class="vbmenu_option"><a href="profile.php?$session[sessionurl]do=addlist&amp;userlist=buddy&amp;u=$post[userid]"><phrase 1="$post[username]">$vbphrase[add_x_to_buddy_list]</phrase></a></td>
	</tr>
	</if>
	</table>

before the </table> insert your code, such as

<tr><td class="vbmenu_option"><a href="http://yourlinklocation.com">Your link text</a></td></tr>