"en route from" is correct and can be used in written English.
It is used to describe passing through a location or locations on the way to a destination. Example: I took a bus en route from Paris to London.
En route from China to Nigeria, the shoes had disintegrated.
Quotes Goethe: "En route from the Leipzig Anxiety Festival,... I...saw several fiery red balls..
En route from Davenport, Mr. Kerry was staggered to learn by phone of Mr. Rassmann's emergence.
En route from Guardian HQ to Farmilo buildings for Kane show with Helen seamons.
En route from the airport, they saw dead dogs lying on the roadside, they said.
Quotes Goethe: "En route from the Leipzig Anxiety Festival,... I...saw several fiery red balls.
En route from New York to Chesapeake Bay for the famous battle, it almost sank twice.
En route from Key West to the Bahamas, the ships were separated in heavy weather.
En Route From Beijing to London, The 2012 Olympic Torch Takes a 6-Day Breather at the Milan Furniture Fair.
Sunday en route from his home in Queens.
The Boeing 777 disappeared on 8 March en route from Kuala Lumpur to Beijing.
