Since you mention "trailer" my best guess would be that you will not be able to use that connection for satellite. If by chance the cable runs from the outside connection directly to the TV/Cable wall plate you would be able to modify that connection and add an A/B switch to select which connection you are using. If that's not the case then you will need to route a new cable in or simply feed a cable through a slide gasket or open window. You can also easily add an external cable connection on the outside wall directly adjacent to where the satellite receiver will be located.