Didn't your coach come with an external coax cable connector?
If it did, just use that entry point, but plug the wire inside the AV cabinet into your satellite receiver, and not the multi-switch box "cable in" jack where it's very likely connected to right now.
If your coach didn't come prepared for satellite, (or cable-tv for that matter), then your best options have been mentioned by others. Use an existing hole where other wires or hoses are already entering the coach, or drill up from the floor, and not through a wall.
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