https://www.vbulletin.org/forum/external/2009/01/18.jpg
Admin BB Code:

<center><table width="75%" cellpadding="0" cellspacing="0" border="0">
<tr>
<td width="250" valign="top" style="padding-right: 15px;">
<table cellpadding="8" cellspacing="0" border="0" width="100%" align="center" style="border: 1px solid #000000;">
<thead>
<tr>
<td class="tcat" colspan="2">Admin Message</td>
</tr>
</thead>
</table>


<table class="tborder" cellpadding="$stylevar[cellpadding]" cellspacing="$stylevar[cellspacing]" border="0" width="100%" align="center" style="border-top: 0px;">
<tr>
<td class="alt1">
{param}
<br><br>
</td>
</tr>
</table>
</table>
</center>

These form to match your style:
Installation:
OK go to admin cp>Custom Bb Codes> Add New bb code

For the Admin code
Title:Admin Message
BB Code Tag Name:ADMIN
Replacement:Place the code i put on your thread there

Example:test
Description:Put your message between the tags to give a adminr message.

Moderator BB code:
<center><table width="75%" cellpadding="0" cellspacing="0" border="0">
<tr>
<td width="250" valign="top" style="padding-right: 15px;">
<table cellpadding="8" cellspacing="0" border="0" width="100%" align="center" style="border: 1px solid #000000;">
<thead>
<tr>
<td class="tcat" colspan="2">Moderator Message</td>
</tr>
</thead>
</table>


<table class="tborder" cellpadding="$stylevar[cellpadding]" cellspacing="$stylevar[cellspacing]" border="0" width="100%" align="center" style="border-top: 0px;">
<tr>
<td class="alt1">
{param}
<br><br>
</td>
</tr>
</table>
</table>
</center>
Installation:
OK, go to Admin CP>Custom BB Codes> Add New BB code

For the mod code
Title:Moderator Message
BB Code Tag Name:MOD
Replacement:Place the code i put on your thread there

Example:test
Description:Put your message between the tags to give a moderator message..


If you use these BB codes combined with the Advanced BB code permissions hack it works great on sites.

Advanced BB code Permissions Hack
http://www.vbulletin.org/forum/showthread.php?t=122942