I had to call a shell script in the script I posted here.
I did so using set CheckSum to do shell script "/usr/bin/openssl sha1 " & quoted form of thePath so I’m guessing what you are looking for will be do shell script "path/command " & quoted form of *variable containing the instruction for getting the video* & "path to your global inbox"
That’s assuming your command wants input along the lines of command URLofVideo [switches] path to folder video should be saved in
Presumably the URLofVideo can be extracted from the bookmark? So you’d do something along the lines of set theURL to thebitoftheURLwhichyouwant, either using regex or if the basic URL format is always the same, using offset and/or texts.
The path to your global inbox will typically be /Users/USERNAME/Library/Application Support/DEVONthink 3/Inbox.
You’ll find the forum quite helpful when you’ve put together your first attempts and get stuck 