How to make iCal move Todos to different calendars?

AppleScript newbie here.
I’m trying to get iCal to move a selected set of todo elements to another calendar. “set” doesn’t work, “move” sends the todos to a deep abyss from which they are never heard from again, “duplicate” does nothing. I’ve even tried to recreate a new todo in the destination calendar with the same properties as the old todo, but when I wrote the code, Script Editor chewed it up and spat it out on my face, after which followed diabolical laughter.

I’ve been grappling with what seems to me to be a very simple problem for five hours, now - can someone please help?

Model: MacBook Pro
AppleScript: 1.10.7
Browser: Safari 419.3
Operating System: Mac OS X (10.4)