Using AppleScript "execute" command in Acrobat

Question

Acrobat's scripting dictionary has a cryptic description of an "execute" command that is supposed to execute a menu item "as if a user clicked it".
No information is given as to how to identify the desired menu command except "reference". Huh? Is there documentation or a tutorial on this anywhere?
Related question, how can AppleScript identify auxiliary windows such as the Document Properties window and its various button bar items and other fields?
Here's one simple thing I'm trying to accomplish: I'm using System Events to script some items like keywords in the Document Properties window. Sometimes it takes several seconds for a document to open. Without putting in huge wait loops, I'd like to execute the menu item "File: Properties..." and then wait for the window to open using a loop like this:
repeat until exists <some way to identify the Document Properties window>
end repeat
Any hope of doing stuff like this? I already tore out enough hair trying to get AppleScript's "do script" command to work (only lately having discovered that the script file apparently must be plain text, no Unicode).

Answer 1

The Macintosh keyboard does not have a true "Enter" key any more - not on the MacBook Pro or the iBooks. Modifier keys do not seem to work either. I've turned on the System Prefs > Keyboard & made it appear in the top Menu Bar. From this menu choose "Show Keyboard Viewer" to see how keys + Return are displayed. Only the Function key changes the Return key. Function + Delete is a forward delete. But Function + Return is just another Return. So any highlighted text is deleted! Command + Return stays on the same line and selected text remains. I will try KeyRemap4MacBook utility then consider buying a USB numeric keypad. Urggh.