If you want to do it with events you can give the animations number names like (1,2,3,...). Or even better numbers in combination with a word like (run1,run2,run3...). Then you can use the set animation action with the expression "run"&n where n is an index.
If the object has animations you can use something like type.animations to get the name at index i. You can glean more info about it by looking at the sprite object's source.