Of course it’s possible !
In your « Mods » folder in the TE4 folder, create another folder with whatever name you want, « MySuperMod », for example.
In this one, you just have to create a « Courts » folder, and you will be able to put all the courts you want.
Rename each court folder « Court_Mod01 », « Court_Mod02 » and so on.
In each court folder you have to put the court.png and the court.ini of the court you want, and that’s all !
Just one thing, you have to verify that there isn’t a « Focal » line in the court.ini.
In this case, replace this line by this :
Focal = // This turns off the default Focal
Thanks for your advice Adriatino, I managed to import the fields into TE4. However, the fields are playable in warm-up mode but it's more complicated in the world tour.
I guess there is something to do to match the right court with the right tournament in the World Tour.
For example, when I start the Doha tournament, I don't play on the Doha court but on a UK court.
It seems that only one court is playable per surface : as soon as it's a clay court tournament, it's always the Roland Garros court for example.
Do you have any idea ?