Choosing combo box item with AppleScript doesn't trigger item action - applescript

Question

I'm trying to use AppleScript to click an item in a select box.
When clicking the 'More...' item manually with the mouse a standard OSX file chooser dialog opens up, but when I try to do it using AppleScript, the 'More...' item shows up as the chosen item for the select box, but no dialog shows up.
So far I've tried... (element names came from Automator recorder)
tell application "System Events"
click static text 1 of window 1 of application process "DYMO Word Addin"
-- combo box arrow
click UI Element 1 of combo box 2 of group 1 of window 1 of application process "DYMO Word Addin"
set labelsList to (list 1 of scroll area 1 of combo box 2 of group 1 of window 1 of application process "DYMO Word Addin")
set numLabelsInList to (count text fields of labelsList)
set theTextField to (text field numLabelsInList of labelsList)
if numLabelsInList > 1 then
repeat with z from 1 to (numLabelsInList - 1)
key code 125 -- down arrow
end repeat
end if
-- stuff I've tried
click theTextField
keystroke return
key code 36 -- return
set focused of theTextField to true
set value of attribute "AXFocused" of theTextField to true
perform action "AXConfirm" of theTextField
end tell
... and now I'm out of ideas.

Answer 1

After a bunch more testing, it turns out that the file dialog only opens when the combo box has focus, and that clicking the combo box arrow button and menu items doesn't actually give it focus.
http://lists.apple.com/archives/accessibility-dev/2006/Oct/msg00013.html
After trying all of the methods from that thread to give the element focus, even 'click at' didn't work.
https://apple.stackexchange.com/questions/40141/when-mousekeys-are-on-how-do-i-click-or-move-the-mouse-using-applescript#answer-40859
That answer recommends cliclick as another way to move and click the mouse, which worked.
So in the end I ended up with
click static text 1 of window 1 of application process "DYMO Word Addin"
set labelsComboBox to (combo box 2 of group 1 of window 1 of application process "DYMO Word Addin")
tell labelsComboBox
set {xPosition, yPosition} to position of labelsComboBox
set {xSize, ySize} to size
end tell
set {realXPosition, realYPosition} to {(xPosition + (xSize div 2)) as string, (yPosition + (ySize div 2)) as string}
do shell script "/usr/local/bin/cliclick m:" & realXPosition & "," & realYPosition & " dc:" & realXPosition & "," & realYPosition
-- combo box arrow
click UI element 1 of labelsComboBox
...

Answer 2

Here you can find someone with a similar question and the answer was also cliclick
https://discussions.apple.com/message/17662850#17662850