I was refering to the theme.php, as posted by z_bull.
the {ADMIN_MENU} doesn't belong to this file, but it is called into play theme.php, as here in the hardwired theme.php,in the // HTML template for the album list section
<td width="100%" height="100%" valign="top" class="tableb_compact">
{ADMIN_MENU}
<p>{ALB_DESC}</p>
<p class="album_stat">{ALB_INFOS}</p>
</td>
</tr>
</table>
</td>
<!-- END album_cell -->
However, z_bulls theme.php has an empty cell where it is called in the usual theme.php
EOT;
// HTML template for the album list
$template_album_list = <<<EOT
<!-- BEGIN stat_row -->
<tr>
<td colspan="{COLUMNS}" class="tableh1" align="center"><span class="statlink"><b>{STATISTICS}</b></span></td>
</tr>
<!-- END stat_row -->
<!-- BEGIN header -->
<tr>
<!-- END header -->
<!-- BEGIN album_cell -->
<td width="{COL_WIDTH}%" height="100%" valign="top">
<table width="100%" height="100%" cellspacing="0" cellpadding="0">
<tr>
<td colspan="3" height="1" valign="top" align="center" class="tableh2">
<b>{ALBUM_TITLE}</b>
</td>
</tr>
<tr>
<td colspan="3">
<img src="images/spacer.gif" width="1" height="1"><br />
</td>
</tr>
<tr height="100%">
<td align="center" height="100%" valign="middle" class="thumbnails">
<img src="images/spacer.gif" width="{THUMB_CELL_WIDTH}" height="1" class="image" style="margin-top: 0px;
margin-bottom: 0px; border: none;"><br />
<a href="{ALB_LINK_TGT}" class="albums">{ALB_LINK_PIC}<br /></a>
</td>
</tr>
</table>
</td>
<!-- END album_cell -->
<!-- BEGIN empty_cell -->
<td width="{COL_WIDTH}%" height="100%" valign="top">
<table width="100%" height="100%" cellspacing="0" cellpadding="0">
<tr>
<td height="1" valign="top" class="tableh2">
<b>&nbsp;</b>
</td>
</tr>
<tr>
<td>
<img src="images/spacer.gif" width="1" height="1"><br />
</td>
</tr>
<tr height="100%">
<td width="100%" height="100%" valign="top" class="tableb_compact"></td>
</tr>
</table>
</td>
<!-- END empty_cell -->
<!-- BEGIN row_separator -->
</tr>
<tr>
<!-- END row_separator -->
<!-- BEGIN footer -->
</tr>
<!-- END footer -->
<!-- BEGIN tabs -->
<tr>
<td colspan="{COLUMNS}" style="padding: 0px;">
<table width="100%" cellspacing="0" cellpadding="0">
<tr>