Clicking into a VectorWorks Window using applescript

I have been attempting to run an applescript that will allow me to creat a rectangle in VectorWorks just by entering a couple of variables. I have run into a problem. I can get the program to open, select the rectangle tool, enter the dimensions and then I get stuck. I have attempted to get the script to click the checkbox that is automatically selected to position the rectangle at the next click so that I could just enter the location that I want the rectangle to be in, but the click happens and does not deselect the check box. I have tried to set the value of the checkbox to “0” to have it be deselected as well. I have also tried to go a different route and have it position the rectangle at the next click and then have the UI click into the window, with no luck either.

Any ideas?

tell application "Finder"
	activate
	display dialog "What Size Rectangle Would You Like To Make?" & return & return & "A" default answer "" buttons {"Cancel", "OK"} default button 2
	if the button returned of the result is "OK" then
		set the a1 to the text returned of the result
		display dialog "B" default answer "" buttons {"Cancel", "OK"} default button 2
		if the button returned of the result is "OK" then
			set the b1 to the text returned of the result
		end if
	end if
end tell

delay 1
tell application "Finder"
	activate
	open document file "COVER DEFAULT" of folder "Desktop" of folder "beibert" of folder "Users" of startup disk
	tell application "VectorWorks"
		activate
		--tell application "System Events"
		--keystroke "w" using {command down}
		--end tell
		delay 2
		tell application "System Events"
			keystroke "rr"
			delay 2
			keystroke b1
			delay 1
			keystroke tab
			keystroke a1
			delay 1
			
			(*keystroke tab
			keystroke "24'"
			delay 1
			keystroke tab
			keystroke "8'"*)
			delay 1
			(*set value of checkbox "Position At Next Click" of window "Create Rectangle" of process "VectorWorks" to "0"
			*)
			delay 1
			--click checkbox "Position At Next Click" of window "Create Rectangle" of process "VectorWorks"
			delay 1
			keystroke return
			tell process "VectorWorks"
				click at {500, 500} (*window of process "VectorWorks" at {100, 100}*)
			end tell
		end tell
	end tell
end tell