QXP Syntax for "get unicode number of selection"

Hello, Found this script, to give up the ASCII number for the selected character:

tell application "QuarkXPress"
	tell document 1
		if tool mode is not contents mode then
			set tool mode to contents mode
		end if
		set x to text of selection
			set y to character 1 of x
			set z to (ASCII number (y))
			display dialog (z as text)
		end try
	end tell
end tell

Anyone know how I would come up with the Unicode number for a selection? And would it be possible in QXP 6.5, or would it have to wait til v7…? (I couldn’t find “unicode” in the 6.5 dictionary)