Using Applescript with OO is easy, at least if you don't have to figure out how to write Applescript :-)
There's an excellent description of how to set it up over in one of the OmniFocus forums, in
http://forums.omnigroup.com/showthread.php?t=7453
Read Rob's directions very carefully as some things that seem like they don't matter, do! If you get stuck, just post again...