Automator Action
Create new Entourage Message with Bcc
Optional: Place this script in the Applescript action if you want the window to be moved out of the top left corner.
tell application "Microsoft Entourage"
set theWindows to every window whose class is draft window
repeat with aWindow in theWindows
set position of aWindow to {75, 140}
end repeat
end tell
Save as Workflow and place in the Entourage Script Menu I Items folder. Add a shortcut. Check out the Sample Automator Workflows in the folder.