Thank you greatly for your help.
This is what I came up with, in case it might be of use to others, or can be improved.
I did end up changing the cookie path to '/' as the site is also using a blog that I would like eventually to tie into Gallery as well, so there is a common user base, and that would facilitate it should I get to that point.
I put this code in a file in Gallery2's root, then included it in my admin page (again, so I can reuse it as needed). Of course all the print stuff is in the chat page, but here for consistency.
Thanks again,
NotGoddess
<?php
//
// By (10%) NotGoddess, and (90%) Valiant @ Gallery forums
// A somewhat hacked tie-in to easily allow access to Gallery2 user data.
// For use by the ChatBox script.
//
require_once('embed.php');
$ret = GalleryEmbed::init(array('fullInit' => true));
if ($ret->isError()) {
print $ret->getAsHtml();
exit;
}
list ($ret, $isSiteAdmin) = GalleryCoreApi::isUserInSiteAdminGroup();
if ($ret->isError()) {
print $ret->getAsHtml();
exit;
}
$user = $gallery->getActiveUser();
$who = $user->getfullName();
?>
<p>Welcome, <?php echo $who; ?></p>
<?php
if (!$isSiteAdmin) {
?>
<p>In order to access ChatBox Administration, you must first
<a href="http://mydomain.com/gallery2/main.php?g2_view=core.UserAdmin&g2_subView=core.UserLogin&g2_return=http://mydomain.com/chat/admin.php" title="Login to Gallery">Login</a>
to Gallery as an administrator.</p>
<?php
} else {
?>
<p>As a ChatBox Administrator, you have the following commands at your disposal [...] yada yada [...] </p>
<?php
}
?>
provide some lines to pop in my PHP script, I'd be a joyful person.