Hi
Unlike animated GIFs that can be made to repeat continuously VP is designed to create films that start and finish. I don't know of way that you can create an "endless film". If the sequence you have created is not too long, you could simply add it to itself as many times as you wish, so as to create a long movie that simply consists of the same sequence repeated over and over again, but at some point it will have to finish.
On the other hand you could play your sequence with Windows Media Player set to "Loop"
Nat