Thank you very much for your answer, this explains the behavior of ICEM.
I was able to load my scripts into gui_interp at startup ICEM:
ic_gui_set eval source test1.tcl
Apparently I misunderstood the documentation:
"All 4 methods can be used with the GUI displayed, but only the last two can be done in batch mode. source D:/user/script.tcl can be typed in the message window, or ANSYS ICEM CFD can be started in batch mode by adding the -batch argument to the ANSYS ICEM CFD startup command (icemcfd -batch). Then you can source the script from the shell."
You are navigating away from the AIS Discovery experience