For anyone wanting to know:

Use these:

$subject = $lang_register['WelcomePM subject'];
etc.

Then put each item in the language files.

The language files parse html correctly.

For apostrophes use "\'"
Quotation marks are fine as is

How did you get the admin name to correctly parse from the database without me having to name it?

If anyone could lead me in a solid direction for a plug-in, I would be eternally grateful. All my attempts seem to not work right.

Is there anyway to make all three fields editable via a plug-in, through the db? I see that I need to add an option to the database, but what after then?

Okay, quick question.

How do I use "htmlspecialchars" on these fields? The text I entered won't parse with quotation marks or apostrophes (of course).

And, how do I link this all to a language file?

Thanks!

In register.php, find:

    // Get admin username
    $db->query('SELECT username FROM '.$db->prefix.'users WHERE id=2') or error('Unable to get username', __FILE__, __LINE__, $db->error());
    $admin_username = $db->result($result);

Replace with:

    $admin_username = 'xSDMx';

This might work for you:
http://punbb.informer.com/forums/post/87006/#p87006

Then just save the file AP_Mass_PM.php in the 'plugins' directory. You would then be able to access the 'Mass PM' plugin under the plugins menu in the admin control panel.

Thanks for the help! I'll look into the editable values, I assume it's the same as with any other plug-in.

$message = 'Welcome to forum message.';

Add after

$admin_username = 'xSDMx';

Thanks for the link.

The mod, however, sends a PM with the user/sender field blank. And, is there anyway to have those values editable via a plug-in?

Thank!