ACP > your style > template > moderator_bar > Find this lines
Code:
<span class="itemCount {xen:if {$session.reportCounts.total}, 'alert'}">{$session.reportCounts.total}</span>
</a>
</xen:if>
Add these code below of the line
Code:
<xen:if is="{$visitor.is_admin} AND {$session.canAdminUsers}">
<a href="admin.php?users/moderated" class="userModerationQueue modLink">
<span class="itemLabel">{xen:phrase users_awaiting_approval}:</span>
<span class="itemCount {xen:if {$session.userModerationCounts.total}, 'alert'}">{$session.userModerationCounts.total}</span>
</a>
</xen:if>
Save and your done :D!