Hi Canshitto,
Welcome to the forum.
If you have version 1.4, then you have the Mission Editor that you can use to create your own missions.
Your fist step should be to download and study the Mission Editor tutorial and the Missions Manual.
You can get them from this topic:
http://80.95.161.114/shipsim/forum/index.php/topic,2886.0.html (http://80.95.161.114/shipsim/forum/index.php/topic,2886.0.html)
The best place to ask questions about making missions is in Development corner > Mission Creation.
You can also ask me by either a PM or by email at the address in the tutorial.
Regards,
Marty