Sounds cheesier then Mount Cheddar.
I think Flash CS4 is the program you are looking for.
It's expensive to buy, but you can get a trial since you're doing this one thing.
It's really easy to use and can do the thing you want in minutes.
I am an experienced Flash CS4 user and could probably do this in literally 30 seconds with Flash.
Another option is to use Gimp, an extremely popular free photoshop-like image manipulator with Gap, a plugin for gimp that is especially made for animating stuff and is often used in high-budget movies (Star trek and Harry Potter are a couple) to touch up special effects.
I will warn you though, Gap wasn't created for the inexperienced user and is alien to most people.