Q:

Applescript to click checkbox in cell in row in outline

I have a checkbox in the following hierarchy:
Outline->Row->Cell->Checkbox
This is how it looks in accessibility inspector:

I need to click on it.
So, I tried:

click checkbox 1 of cell 1 of row 3 of outline 1 of scroll area 2 of splitter group 1 of tab group 1 of window 1

This gives the error: 
Expected end of line, etc. but found number.
If I try to select the row like this:

select row 3 of outline 1 of scroll area 2 of splitter group 1 of tab group 1 of window 1

The row is getting selected.
Also, I can read the properties of the row like so:

get properties row 3 of outline 1 of scroll area 2 of splitter group 1 of tab group 1 of window 1

but not the properties of the checkbox/cell using:

get properties of checkbox 1 of cell 1 of row 3 of outline 1 of scroll area 2 of splitter group 1 of tab group 1 of window 1

I'm an absolute n00b at applescript, I have no, I idea what is going wrong.
Can anyone help?
PS: I am trying to turn off the screenshot shortcuts with in system preferences.

A:

It's choking on the specifier for AXCell. Cell doesn't work. Just use UI Element 1:
tell application "System Events"
    tell process "System Preferences"
        click checkbox 1 of UI element 1 of row 3 of outline 1 of scroll area 2 of splitter group 1 of tab group 1 of window 1
    end tell
end tell

