Thank you for your answers.
Jackie, I tried to create a load module with your subroutine sample, but I get an error message in IUA function: load module cannot be loaded.
I've been using f77 to compile the .f file, and the "shared" command to generate the load module.
I also set the catia.iuamodule_usr to the right directory.
If you have an idea, let me know
Regards