This can be done via Javascript. For more details, check out the [url=http://www.adobe.com/devnet/acrobat/pdfs/js_api_reference.pdf]Javascript for Acrobat API Reference[/url].
Lori Kassuba is an AUC Expert and Community Manager for AcrobatUsers.com.
Also look at [url=http://www.acrobatusers.com/tech_corners/javascript_corner/tips/2006/folder_level_scripts/]Entering Folder Level Scripts[/url] and [url=http://www.windjack.com/resources/howto/WJHowTo_JS_Folder_LvlDev.php]Some Notes on Developing Folder Level JavaScript[/url] by Thom Parker for more information about creating the folder level scripts needed to add toolbar buttons and menu items.
Lori Kassuba is an AUC Expert and Community Manager for AcrobatUsers.com.