Trailer problem

Now we have a problem. I bought a boat in Holland and it’s on a trailer. In Holland this type of trailer does not require its own license plate; instead it has to have the license plate of the car towing it. Now I plan to take this boat to Sweden, the country where all trailers have to have their own registration plate. It is not allowed to have the license plate of the car towing it on the trailer. So How am I going to take this trailer to Sweden? The Swedish authorities advised me to ask for a temporary registration in the Netherlands and the Dutch authorities tell me that they do not have such a temporary registration and cannot help me.