Duplicate picture box


I am trying to duplicate picture boxes in quark using applescript and need to be able to position them precisely on the page if possible. Here is the script I have so far:

tell application "QuarkXPress"
	tell front document
		set BoxToCopyList to {}
		set boxCount to count every picture box
		set copied to 0
		repeat with i from 1 to boxCount
			tell picture box i
					set BoxToCopyList to BoxToCopyList & uniqueID
					set copied to copied + 1
				end try
			end tell
		end repeat
		display dialog "A total of " & copied & " picture boxes will be copied." buttons {"OK", "Cancel"} default button 1
		repeat with i in BoxToCopyList
			tell (every picture box whose uniqueID = contents of i)
				duplicate to before picture box 1
			end tell
		end repeat
		say "finished"
		display dialog "The " & copied & " picture boxes were copied successfully." buttons {"OK"} default button 1
	end tell
end tell

This obviously only duplicates the picture box to in front of the box being duplicated, what I actually require is for the box to be positioned with a horizontal offset of the original of -77mm is this possible using applescript? Any help would be greatly appreciated.