[wp-hackers] Adding Admin Link to Certain Page

[Chris Poteet]

I have two questions.

Is there a way to add an admin menu to a specific page and not just a
new panel. For instance, I would like to add a link underneath
"Appearance" that will link to the plugin editor page and load a CSS
file. Is it possible?

/wp-admin/plugin-editor.php?file=persistent-styles-plugin/
persistent.css&plugin=persistent-styles-plugin/persistent.php

Also, where is the documentation to put a custom message in the update
panel for a plugin?