I think it'd be easiest to just duplicate the sprite with the same name on all your other maps. Unfortunately there's no automated way to do this, but it's relatively easy to load the sprite definition/template from your first map, then switch to a path for another map, type the template name, and hit the "Create" button there. (This problem was eliminated in version 2 because I realized the folly of my ways and allowed sprite definitions/templates to be shared across maps.)
Strangely, actual users of the program probably know better than I do how to use the scripting wizard to create shots that can be used on multiple levels. That's my guess of how it would be done, but I've never actually used the scripting wizard to make a multi-level shooting game myself. Can anyone confirm that this will work?