So what happens if you've never created a mission in the ME, and the scenario maker has not provided a user_camp.txt file? Can you just make your own txt file, put in the appropriate lines, and change the suffix to engcfg?
That's right, it can be done. Just create something like this, replacing the text in red with the required mission entry:
user1()
{
Hetzer_01, Hetzer_01, 1, 0, hetzer_01.tga, txt_cit_01, 30, txt_hist_intro, hist_map_teach, levels\levels\cm_users\Hetzer_01.level;
} //end of user1
And save it as user_camp.engcfg.
All of this can be done quickly and simply in 'Notepad'.
It pains me to note that many people aren't familiar with 'Notepad'.
Incidentally, the 'user_camp.engcfg' should appear automatically once you've started creating your own missions.
The catch is making your own shortcut to the Mission Editor. Many people haven't figured it out yet and it pains me greatly also.