Applescript command that navigates to a specific folder when the attachments popup appears in safari?

Question

I'm building an Applescript that will attach specific files when the attachment prompt appears in Safari.

I initially tried do shell script "open /Users/ea/Desktop/Guru/Deliverables/" but that just opens a new finder window. I need to know how to navigate to the correct folder once the prompt appears (see image below).

I'm sure it's simple, but I'm brand new to Applescript.

Answer 1

The GUI script solution would be:

tell application "System Events" to tell process "Safari"
    tell window 1 to tell sheet 1
        key code 5 using {shift down, command down} --shortcut for go to folder
        tell sheet 1
            set value of text field 1 to <POSIX path to targetfolder as text>
            click button 1
        end tell
    end tell
end tell